You will need to install a user script manager extension to install this script.
Personal script i share with you.
As the Name said: This script, in Photo Page, AUTO Load More Preview thumbnails (without clicking) on HOVER of the Mini Thumbnail.
► It help to Fight these New Flickr Adds (2019):
I hide them. But if you navigate in Photo pages with the arrows buttons, after viewing 4 shots, a Pub is inserted (but hidden by me) Solution: Use the "Mini Thumbnail" and choose the shot you want to see, like that no adds !
▶ Work well with this 2 Userstyles (by me): Move the Mini Thumbnail to the Top Right side (near the comment form, under the user Buddy Icon). On hover, it is expanded and more thumbnails are loaded in it without clicks)
▶ And for a dark gray flavour: Flickr WideScreen - Dark & Grey
OR ▶ NEW (2020.04): To install all parts of "Flickr Widescreen - ALLinONE TOTAL" at once, you can use my userscript [Greasyfork]: Flickr WideScreen - BigONE v.120 - TEST UserCSS style
Greasy Fork now supports User CSS as defined here for use with Stylus or as UserScript, read: [Beta] User CSS support