Quick Compare
Quick compare lets you launch the viewer in compare mode on two assets without adding them to the compare+ module.

The quick compare module, without assets
Quick compare is in the assets module, beside the upload/create folder buttons. It is available from any folder and the search results. Select one or two assets and click the ‘Add to quick compare’ button or use the context menu.
Quick compare has two slots for assets. The number indicator shows how many slots are filled. When both slots are full, launch the “compare assets” action to open the viewer.

The quick compare slots, after clicking the number
Click the number to view the asset slots. You can delete an asset or clear all by clicking the cross.