I like the drop-downs that let you play with the search results. Both the search and filter are very responsive, which makes it fun. These will be awesome features as the volume of publications grows.

Some of the drop-downs should probably be comboboxes. Tags and lists, for instance, can have a near-infinite number of names. I should be able to type out tags, as well as pick them from a list.

I think the clear button can be moved within the search bar as a little "X" icon. "Clear" is a "negative" action, and we typically want to put less visual weight on "negative" actions. That's just a UI nitpick, though.

I also noticed how the colored boxes act as placeholders while images are loading. I appreciate that; it's an elegant UI.