It shows the item!
Closer view of the model
Showing the comparison tooltip as well
The basic config screen
An item tooltip, with attached model preview, for a known appearance. Clothes have been automatically removed from the preview so the shirt can actually be seen.
The appearance has been collected, but not from this item. It's also a non-class item, so it warns that you won't get the transmog.
It lets you know if an item's appearance can't be collected.
Zoomed in on a helm
Zoomed in on a weapon
A filter!
This shows the integration with the default bags. It's showing a purple eye for unknown appearances, a blue eye for known but-not-from-this-item apperances, and an envelope for items you can't learn on this character.