The solution above is actually for "Please No More!" - You were completely stripped.
This trophy is "And You Were Never Heard From Again" - Did all the naughty things in the dressing room.
In the changing room, press

and then

to zoom in and rotate the image of the character.
Perform all the actions required to elicit a reaction; a reaction is required for each one for the trophy to trigger.
* zoom in the camera to focus on her face, breasts, butt (front & back)
* hold

and tilt your vita to peek at her underwear.
* hold

and tilt your vita to look at a low angle, and blow air in the mic to lift up her skirt.
* touch: face, back, breasts, butt (front & back), and underwear - to touch underwear it's best to hold

and tilt.
* Lift up her skirt using the touch screen - I found this one the hardest to generate a reaction. I almost had to flick the skirt up to get it high enough.
* rub both breasts gently with two fingers, one finger for each, and gently separate them and hold. Keep holding until she reacts. And then release

.
* rock your vita back and forwards to shake her breasts. I found a pivoting motion, so they shake side to side, best.
* rub the front and back touch screen together in the same place - you are doing it right if blue circles appear and a combo builds up - so you break her clothes. Do it until she is left in only her underwear.
It doesn't appear that all actions are required in the same visit to the changing room.