Have you taken a look in your photo album recently? There are now 129 unique photos that you can collect by playing through Poptropica Islands. And each one records what you were wearing at the time the photo was taken, so that you can costumize from it later!
You can see your photos from your Poptropica Friends profile page. Just click the Friends icon at the top right of your game screen to get there. And then... say cheese!