"Talent," (gaenggi) as far as I've experienced watching K-variety, refers mainly to imitations. Usually of a celebrity, drama character, or animal, but I've seen someone's "talent" be an impromptu patter in the style of tv home shopping channels.

I vaguely remember that displays of dancing or martial arts have not been referred to as gaenggi, but skills.

I don't think people who slut-shame Hyuna care that she screams at chickens, so it doesn't seem like it's the image switches that cause any unease. Her performance demeanor is the only one they consider. Besides which, the image switch is a staple of idolling. Every single-group/idol fan proudly proclaims that their bias is the most charismatic/sexy/hot on stage and the most dorky off. Antis never attack that they act dorkily in variety. Rather, often they get hate when they act too much like their performance modes (arrogance and/or aloofness often being demanded of them by the music genres they perform) outside of it and come off "rude."