There is a strong assumption here that you could encourage hundreds of people to express their opinion on this someone's shirts.
The value for the poster is clear; what is the value for the voter?
The value for the poster is clear; what is the value for the voter?
It would also be important to make it very fast. Cache all the images before the voter gets there, and send the results asynchronously so they don't need to wait. One could easily do a rating in less than a second. It's all snap judgements.