The cart symbol in the corner of the photo and video thumbnails makes it possible to easily select multiple items from multiple albums (▼)
After your add an item , it is added to the panel at the bottom right corner - lightbox (▼).
After your selection is completed, you may use the "Buy" button from the lightbox (▼) to open the product panel for all of the selected photos and/or videos. It is the simplest way to choose the photos/videos you wish to buy as it is impossible to select an item twice, the lightbox can be easily minimized, and removing any or all of the items just can not be easier.
The "Clear" button simply clears your selection and hides the lightbox, since it has no use without any selected photos and/or videos. The last button minimizes the lightbox so that only the number of selected photos and a link to restore the lightbox are visible. The minimize button allows you to concentrate on choosing new photos.
Tips and Tricks
You can easily use this option to buy photos and videos by different users. Once you press the "Buy" button while the lightbox contains items from various sources, the product panel will at first allow you to choose a group of the items to be purchased (▼). Only these items will be added to the cart but the lightbox will still include all the starred items. Once you complete the checkout for the first chosen group, you can press the "Buy" button again and select another group. Moreover, the lightbox is associated with a browser session, therefore you can easily return to it days later unless you delete the bluemelon cookies.