See:

• http://kb.mozillazine.org/Images_or_animations_do_not_load

You can use these steps to check if images are blocked:

• Open the web page that has the images missing in a browser tab.
• Click the website favicon (How do I tell if my connection to a website is secure?) on the left end of the location bar.

• Click the "More Information" button to open the "Page Info" window with the Security tab selected (also accessible via "Tools > Page Info").
• Go to the Media tab of the "Tools > Page Info" window.

• Select the first image link and scroll down through the list with the Down arrow key.
• If an image in the list is grayed and there is a check-mark in the box "Block Images from..." then remove that mark to unblock the images from that domain.

Thank you for your help! I tried to uncheck the "block" through the Page info via Tools, but it keeps checking itself. Why would it block everyone's photo albums? I'm so frustrated =(

A check-mark in "Block Images from..." will block all images that come from that server.

You can try to use Tools > Delete browsing, search and download history on Firefox to clear only the "Site Preferences" (make sure to remove the check-mark in the other boxes) to remove all exceptions.

There are also extensions (Tools > Add-ons > Extensions) that can block images.

Start Firefox in Diagnose Firefox issues using Troubleshoot Mode to check if one of the add-ons is causing the problem (switch to the DEFAULT theme: Tools > Add-ons > Themes).

• Don't make any changes on the Safe mode start window.

See:

• Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems

(locking this thread as a duplicate, continue here: /questions/794757)