Usually refers to native island men that chase/pursue white females visiting/vacationing the islands (Jamaica, Bahamas, Nevis, etc). The conquest is often considered a status symbol for the islander men.
similar to “blackfish” or “blackface”, yellowfishing or “yellowface” is attempting to look asian, if you aren’t asian. this may consist but is not limited to: aritificially enlarging the eyes, making the nose smaller (plastic surgery), and pulling / taping back the eyes to make them slimmer / wider.
follower: “omg are you asian?”
instagrammer: “no, haha im *insert race*! thank you though!”
follower (later, conversation with a friend): oh, you know *instagrammer*? yeah, they’re a yellowfish. they arent actuallt asian.”