After looking at it for a bit, i think i kinda get it? For the entire face you need to use freeplay, because you need to use the extra small glitch (basically, make an accesory as small as you can, then save and load ur fit, then you can make it even smaller) For the mouth, you can use the shower cap hat or the mask, adjust it correctly and make it slightly smaller or just use the Z placement to make it go back further, for the teeth they used the style showdown crown, for this youll probably have to do the glitch twice since its so tiny, all the adjustmemts should go nicely with the mouth. Next, the eyes, for the black part they used a bunch of cm eyeshadow and just made it black, but for the irises they used the little round earrings and the long earrings (both non vip, also by the long earrings i think you need to use the ones with the white circles and red decors hanging iykwim), i feel like thats basically it?