Try resetting firefox.
A Refresh can fix many issues by restoring Firefox to its default state while saving essential information like bookmarks and passwords.support.mozilla.org
Try loading firefox in safe mode.
To restart in Firefox Safe Mode to troubleshoot and fix problems, select "Restart with Add-ons Disabled" in Firefox's Help menu. Learn more.support.mozilla.org
Now this isn't windows safe mode but its safe mode for firefox. There might be an addon that is causing this,possibly you have an ad blocker installed that could be causing it?
Is it just one website, do other websites load pics and videos fine such as youtube? Kinda need more information to help you. What website are they not working in?
I don't have another computer to be able to do that. It is really not that important of an issue because I can use Microsoft edge for that site. What do you make of the fact that also half of my desktop icons have lost their image as well ???What if you access that site on a different computer with firefox? Without seeing a screenshot of what it looks like, its hard telling what exactly is going on.
Seems you got some sort of windows corruption going on. The ones that lost their image, what type of file was it?