Fashion Advice is an optional favor in Sleeping Dogs.
Around the corner from the North Point Apartment and up a set of stairs, a girl in a yellow tank top asks for a moment of Wei's time.
Speak to her, and she'll ask if Wei thinks her shirt is too tight while posing for him. As Wei checks her out, a thug hits him from behind and steals $500 from him. Chase the thug.
Eventually the thug stops and gets two buddies to help him. Beat all three thugs, and you'll gain some Face XP and receive your money back.
Rewards: HK $500 (technically not a reward due to the fact that HK $500 was stolen from you during the mission)