Unlike many 4th-generation idols who were street-cast, Haewon entered JYP Entertainment through the highly competitive standard audition process in 2017. She performed Stephanie Poetri's "I Love You 3000" during her evaluations, displaying a vocal maturity that quickly established her as a key trainee. Her training period lasted approximately four years, during which she traveled 90 minutes each way from Incheon to the company building, a testament to her dedication.1

Within the company, she was known for her strict self-discipline and analytical approach to practice, earning her the internal reputation of an "Ace."2 This reliability led to her appointment as the leader of NMIXX, despite not being the oldest member (a role held by Lily). Her leadership style is often described as articulate and witty, bridging the gap between the group's experimental "MIXX POP" identity and the general public.

Haewon achieved mainstream viral fame through her appearance on the web variety show Workdol. Initially a guest, her natural comedic timing led to her becoming the MC for Seasons 2 and 3. She created the "Oemo Check" (Appearance Check) meme during a flight attendant episode3, where her deadpan delivery and confident pose became a nationwide trend, imitated by other celebrities and used widely on social media. Even JYP Entertainment founder Park Jin-young himself praised her variety sense, calling it a "unique talent" he hadn't seen in the company before.4

Despite her comedic persona, Haewon is a formidable vocalist. Her appearance on Begin Again Open Mic in 2024 served as a reminder of her primary identity as a musician. Her cover of Coldplay's "Viva La Vida"5 was widely shared for her distinct vocal tone—clear, powerful, and emotionally resonant. Critics noted her ability to maintain stable pitch and projection even in difficult outdoor acoustic settings, solidifying her position as one of the top vocalists of the 4th generation alongside bandmate Lily.

She frequently showcases this duality on shows like Lee Mujin Service, where she transitions seamlessly from cracking jokes to delivering technically complex vocal runs.7 This balance of high-level performance skill and approachable variety charm defines her unique position in the K-pop industry.6