Yes Sam, as long as your not downloading and/or using them for false purposes or to make money. Linking is different then downloading. Many websites will block you from downloading but not linking. If you've ever tried to download a sound file, for example, and it only "saves target as" that is linking. So you are actually visiting that site to access that file even though it doesn't necessarily look like it. If I downloaded the pictures by right clicking and saving and then posted them as my own or made postcards etc. that would be a different thing.
By the way, anyone can veiw your pictures on that site. You don't even have to be registered. You only have to register to submit your own picture. So you might want to take yours off if you don't want anyone to be viewing them.