she's hypnotised to strip for an art class, amplifying her need for attention by pointing out that she has an exhibitionistic streak.
once naked she can be hypnotised to suck dicks for the art class.
theres a few optional scenes to grind for a promotion after those. the collar she's wearing makes her more susceptible to suggestion.
and theres the bad end, which is my favourite scene in the game due to how devilish an idea it was.
they send a recording of brainwashed sylphy getting fucked silly to voyeur, and the video is laced with hypnotic suggestion to get her aswell