Not anywhere close to the now gone Thumbnail Zoom Plus. It doesn't work on many sites, or only on certain images. Thumbnail Zoom Plus for instance, enlarged every single picture I wanted to, including users profile images and allowed me to enlarge images endlessly to the extent of my large computer screen.

Unfortunately, Thumbnail Zoom Plus is not the only add on left behind when Mozilla updated to version 57. As a side note, a few weeks after installing, the browser seems to be slowing down. And for love of.... please find a way for the user to override auto refresh (Java?) that's beyond the currently built in option. Update: removed permanently on 07/12/17.