Carey worked with various songwriters and producers on the project, including Jermaine Dupri, Bryan-Michael Cox, Stargate, The-Dream, Tricky Stewart, Scott Storch and Danja.

Although it shared similar vocal production as well as an inclination to her signature pop and R&B ballads, the album also encompassed a variety of dance-oriented and uptempo styles.

Though considered by critics very similar to the formula its predecessor had been built on, E=MC² included other genres she had never explored, such as reggae, and her continued recording of gospel-influenced hymns.

Although hailed by critics, and expected to have achieved large commercial success, the song stalled at number nineteen on the Hot 100, and managed to chart weakly internationally.

[22] In describing the cover, Macpherson wrote "Carey is naked but for the world's largest feather boa, an accessory for which flocks of birds have surely given their lives.

"[19] Music critics compared E=MC² heavily to Carey's previous album, The Emancipation of Mimi, and felt it followed the same formula of ballads and dance-able tracks.

[23] Lyrically, the song finds the singer during a night out, migrating from several locations: from the car to the club, from the bar to the V.I.P, from the party to the after-party, and finally to the hotel.

The song's hook is built around a piano melody and "circular keyboard line", and features "a stuttering mid-tempo beat that's accented by finger snaps and electronic synthesizers" as its instrumentation.

According to Ben Ratliff from The New York Times, it's a "questionably sexy striptease: a goofy-sleazy tryst vignette", with Carey singing "If there's a camera up in here then I best not catch this flick on YouTube.

[30] The lyrics read "Keepin' me there, under your thumb / Cause you were scared that I'd become much / More than you could handle," she confesses, and refers to herself as "Shining like a chandelier / That decorated every room inside / The private hell we built / And I dealt with it / Like a kid I wished / I could fly away.

"[30] Sarah Rodman from The Boston Globe described it as "another look at her fractious marriage to Mottola", and wrote "Although the union ended in 1998, Carey is still suffering, including dreams of the 'violent times' and 'sleeping with the enemy'.

"[29] MTV News writer Jennifer Vineyard described the song in detail: [It] finally reveals a side of Mariah we don't see that often — her true self.

Critics also noted how "I'll Be Lovin' U Long Time" "recalls" the melody riff[38] and chord progression[28] of the Hill Street Blues's theme song.

[39] Lyrically, the song was described by critics as a "larger than life anthem",[40] and an "inspirational lighter-in-the-air ballad",[41] and finds Carey remembering both her father, as well as any lost loved ones.

Similarly, "I Wish You Well" incorporates gospel influence into its melody of "rousing piano waltz", that "extends forgiveness to those who have wronged her in the past and is pretty much interchangeable with its predecessors.

Accompanied by a piano and some multi-tracked backing vocals, Carey sings: "Still bruised, still walk on eggshells / Same frightened child, hide to protect myself / But you can't manipulate me like before."

Tamara Jones of The Washington Post jokingly commented on Carey's flailing hand movements during the performance, writing how she was "waving like a malevolent homecoming queen".

[52] Gil Kaufman from MTV News complimented Carey's performance, commenting on her "barely there micro-dress" and writing how she "serenaded the audience with her homage to lost ones.

[60] During the set-list, Carey was accompanied by six men in black ties, who hoisted her into the air in front of over 6,000 people during "Obsessed", and rigorous dance routines throughout "Touch My Body".

[60] Similarly to American Idol, Carey was featured as a guest judge and musical act on the fifth season of the British talent competition, The X Factor.

[63] According to reports, the episode gained a large increase in viewers due to Carey's presence, and was able to surpass its long-time rival program, Strictly Come Dancing, in the ratings.

"Touch My Body" became Carey's eighteenth number-one on the Billboard Hot 100 and made her the solo artist with the most number one singles in United States history, surpassing the record held by Elvis Presley.

[86] The song's accompanying music video was filmed by Carey's then-husband, Nick Cannon, and features her as a dancer in a Las Vegas show at the Bellagio Hotel and Casino Resort.

[87] During the show and its preparations, Carey realizes that her ex-lover has found love with one of her fellow dancers, leading her to blow up the car he gave her, as well as its accompaniments in the Mojave Desert.

[94] Stephen Thomas Erlewine, senior editor of AllMusic, rated the album three out of five stars, and wrote "it's misleading to judge Mariah based on her new record of possessing the most number one singles, as she's not about longevity, she's about being permanently transient, a characteristic 'E=MC²' captures all too well.

[5] She continued complimenting the album's several collaborations, and wrote "the result is a largely enjoyable mix of flirtatious club jams, midtempo love songs, and emotional ballads anchored by hip-hop beats that handsomely showcase the singer's powerful vocal chops.

"[30] Los Angeles Times staff writer, Richard Cromelin, gave the album two out of four stars, noting its "alternatives to the glass-shattering flamboyance of her early '90s youth.

"[96] Ben Ratliff of The New York Times felt the album didn't level up to par with Carey's previous release, writing "Much of the record sounds like urban-radio imitations, without the peculiarities and effective hooks of 'Mimi'.

Sawdey concluded his review on a mixed note, stating " the second act of Mariah's comeback doesn't wisely expand her sound: it instead succumbs to the blueprint so carefully laid out by its predecessor, a pointless remake that exists only because it has to.

"[26] Caryn Ganz from Rolling Stone questioned why she limited her vocal abilities throughout the record, "nearly every song confines Carey to four-note verses, offering little room for her glorious range.