i like how the waterbottle matches the outfit!

sorry for asking so many questions about polyvore!! thx for answering btw!!(I think that this is my last q) When you add the image how do you make it fill the whole collage box? (idk if that made sense) I tried to make the pic the background but it cuts out part of the outfit and if I just expand the outfit then it looks weird...any tips??☺️thanks so much for all of the help btw