Edit: The issue below is now fixed. However, it only gets 4 stars because of the frequency of problems that this extension suffers from. End Edit.
After the last Firefox update, this extension breaks the display of google image thumbnails in image searches. If the Zoom levels are over 108% (on my system = 1080p), all images thumbnails are displayed on the left hand side in a single column. It also breaks many other websites (abcnews.go.com, for example). This is a great extension ... when it works, but it far too often is broken or breaks sites, and it takes a LONG time for fixes. Cannot recommend.