Written largely during the 2020 COVID-19 lockdown, the album conceptually centers on dispelling the stereotypes surrounding single women and dating, with many of the songs based on de Casier's personal experiences with bad partners.

Upon its release, Sensational drew widespread praise from music critics, who commended de Casier's vocals and songwriting, as well as the '90s and 2000s-influenced production.

The album slowly drew attention, appearing on several critics' year-end lists and eventually receiving praise from English singer-songwriter Dua Lipa, who invited de Casier in 2020 to remix her single "Physical".

[8] In early 2020, she was slated to tour further in Australia and the United States, but upon the emergence of the COVID-19 pandemic, she was forced to cancel the shows and isolate in Copenhagen; she then wrote and recorded the majority of the album during the COVID-19 lockdown, at the same time as she finished her final year of studies at university, working towards a Master's degree at the Rhythm Music Conservatory in Copenhagen.

[9] While in isolation, de Casier initially experienced writer's block, but then "realised life doesn’t have to completely stop" and resumed her songwriting.

[5] De Casier stated that she reflected on past relationships as she wrote the record, writing songs describing previous romantic endeavors.

[12] "Polite" details a real-life date with a rude lover; de Casier reflected that she should have simply left in protest, inspiring the lines "You gotta have some manners/If you wanna roll with me".

[10][13][14] "All You Talk About", a reference to Jennifer Lopez's 2001 single "Love Don't Cost a Thing", berates a lover who is overly materialistic.

[4] "Make My Day" mocks the idea of pickup lines at bars, with de Casier uttering lines—such as "When you fell from the sky, did it hurt?

[18] The album—particularly the song "Busy"—was also noted for its departures from the themes of single life and dating, and for its emphasis on self-love, chronicling de Casier's morning routine in "endearingly geeky" detail.

[1][8][17][18][20] Regarding the mood of "Friendly", de Casier reflected that partway through her writing the song, she went to sleep and had a dream set in a jungle, in which she was surrounded by waterfalls.

[26][27] In a May 2021 interview, de Casier stated that the video is modeled on detective movies and reality television, and is shot to give the impression that it's from the point of view of a stalker.

[36] The music videos for the last three singles, beginning with "Polite", all star Bianka, a fictional character created by de Casier who is the CEO of the "Sensational Corporation".

[4][11] De Casier reflected in an interview with MixMag that she had initially been hesitant to appear in the music videos for her new album's singles, but that then "I ordered this wig from a party site, and when I put it on I just felt very empowered".

[10] Bianka's persona of a modern woman looking for love was regarded as an extension of the album's themes, and has been likened to de Casier's own Sasha Fierce or Ziggy Stardust.

[4][10][21] On 17 September 2021, de Casier released the album's fifth single, "Someone to Chill With", with an accompanying music video and announcement of expanded tour dates in the UK, Scotland, Denmark, the Netherlands, and the Czech Republic.

[39] In June 2021, Paste ranked Sensational as one of the ten best albums released in May 2021, praising her for "balancing herself on the same tightrope as her inspirations between relatability and luxury" and the record's "humility" and "confidence".

[53] In July, Nylon featured the album on a list of "12 Criminally Underrated Music Releases of 2021 So Far", with critic Steffanee Wang writing that the songs "linger like a plume of expensive perfume" and singling out "Drama" and "No Butterflies, No Nothing" as highlights.

[59] It was preceded by the single release of Spanish artist Isabella Lovestory & record producer Chicken's remix of "Drama" on 4 November 2021.