Nice icon. Unobtrusive. Works somewhat like others, but nicer looking.
A couple of small gripes...
1. When you click ONCE on a clipping in the list, it should automatically populate the current clipboard slot. Why should we have to double click it or click a separate icon? Too much clicking. No need.
2. The current top most slot is repeated twice. I realize that you're differentiating between the active slot and the archived slots, but anyone who has ever used a clipboard manager knows that the topmost slot is the current slot, and anyone who hasn't used a clipboard manager will figure it out in about 2 seconds. The repeated entry is a waste of space and clutters the UI.
4. If you change the main function to a one-click population of the current slot, maybe you could keep the double click and let it call up the clip for editing. Sometimes we copy too much...let us edit the clip!
5. If you enable copying of (and browsing of copied) images, you'd have a real winner!