It doesn't seem to work on Librefox or FF. It's greyed out under the extension tab on the toolbar, though it shows as enabled under the addon list in FF extension options.

Simple, but effective. I never could make out who was who because of the small pictures.

A small remark: I don't think the Add Age option is working. I'm not seeing an age on the actor profile page.

It prevents lazy load of images, that's exactly what I need.
Thank you very much.