We all know Duo's sentences have context: http://for91days.com/photos/SriLanka/Galle%20Photographer/Mirror-Room-Galle-Sri-Lanka.jpg
I don't think so. I guess 'wish' is closer to the conditional mood and it isn't rude like 'want'. But conditional conjugation hasn't been taught at this point, thus you can't use it yet. Just for the record, it would actually be 'quali specchi vorresti pulire?' with the conditional.