Described as a mid-tempo dance, pop, and trap song that incorporates traditional Korean melodies and Caribbean elements, its lyrics are about overcoming a toxic relationship.

[16] Rhian Daly, writing for NME, praised the poetic lyricism as well as the fresh production of "Flower", naming it one of the best K-pop songs of the year.

Daly noted that the song successfully managed "to mix elegance with inventiveness and elements of modern production with more traditional sounding sonics".

[17] For Rolling Stone, Tim Chan commended the song's "finger-snapping production" as well as Jisoo's confident vocal delivery, which he felt managed to make the lyrics feel very personal as well as keep the listener's attention.

[18] Samantha H. Chung for The Harvard Crimson labeled "Flower" a "classy, laid-back debut", with appreciation for the verses's "sophisticated, mature groove that creates an almost indie sound" and the song's "compelling hook".

"[19] Rolling Stone ranked "Flower" number 67 in their list of The 100 Best Songs of 2023, calling it a "sophisticated track with a staccato, Latin-tinged melody and Caribbean-inspired percussion" that "feels instantly familiar yet unlike anything else on the radio".

[21] "Flower" won 9 first place trophies on music programs in South Korea, including two Triple Crowns at Inkigayo and Show Champion.

"Flower" debuted at number two on the Billboard Global 200 with 108.7 million streams and 21,000 downloads sold worldwide, marking Jisoo's first solo entry and top-ten song on the chart.

It earned the third-biggest streaming start for an artist’s debut track, behind bandmate Lisa's "Lalisa" (2021) and Olivia Rodrigo's "Drivers License" (2021).

[44] In South Korea, "Flower" debuted at number 33 on the 13th issued week (March 26–April 1, 2023) of the Circle Digital Chart, with less than two days of tracking.

[54] In Canada, "Flower" debuted at number 30 on the Canadian Hot 100 and surpassed "On the Ground" as the highest-charting song by a K-pop solo female artist in the country.

She walks around the hotel wearing elaborate gowns while occupied in her thoughts, reflecting on her relationship, describing it as a "spark he simply couldn't handle".

They also complimented Jisoo's "striking beauty looks", which included a floral-inspired updo, minimalist eyeliner, smokey eyes with face jewels, and pastel makeup with faux freckles.

[62] GMA Network similarly noted how each of Jisoo's nine designer outfits showcase her evolving style and underscores her status as a fashion icon.

[60] Glitter Magazine drew attention to the symbolism in the video, including the use of floral imagery and outfit changes to depict themes of heartbreak and independence, showcasing Jisoo's growth and maturity.

[25] On April 8, 2023, Jisoo performed "Flower" for the first time live during Blackpink's concert at the Tokyo Dome as part of the Born Pink World Tour.