You first try on a tubetop that perfectly fits your waist but is still to small in the chest area. Large enough to fit your boobs in but still in danger of falling out with too much movement without a bra. Your tits seem to overflow a bit but you decide all of this is passable because the black ruffled top accentuates your cleavage and would probably look amazing with a open jacket.
Next you try on a crop top that, while exposing no cleavage, make your boobs look fuller and rounder than the last one. This one fit rather well as well but the lack of a solid back meant no bra. For a normal girl (or I guess guy now) that could end up causing a bit of discomfort, but the changes you made lessened the backpain you received from your chest.
The third one you tried on was a black, sleeveless top with a lace window down the middle, you have trouble getting the waist over your chest but once you're through you see feel your boobs squished into and stretching the fabric of the shirt. Your nipples are definitely noticable through the fabric and you decide a bra is probably necessary for this one. Other than that, the cleavage visible through the lace window is a great addition so you struggle out of it and move on to the last one.
It so happens to be the most frilly and feminine of the bunch meaning styles truly did completely swap and the one with visibly the most chest room, it also seems the straps are thick enough to cover a bra so you don your massive cups and put on the white frilly shirt.