It is possible that the images can not be downloaded and that the alt text is displayed instead and only a few characters fit in the space the image would take.

Special icons are usually supplied by an icon font that is downloaded from the server via @font-face CSS rules.

You can check gfx.downloadable_fonts.enabled on the about:config page and make sure it is set to true (if necessary double-click the line to toggle its value to true). Also make sure you allow pages to choose their own fonts.

• Options/Preferences -> General: Fonts & Colors -> Advanced
  [X] "Allow pages to choose their own fonts, instead of my selections above"

You can check the Web Console for font related messages.

• "3-bar" menu button or Tools -> Web Developer

If you use uBlock Origin make sure not to "block remote fonts".

cor-el said

It is possible that the images can not be downloaded and that the alt text is displayed instead and only a few characters fit in the space the image would take. Special icons are usually supplied by an icon font that is downloaded from the server via @font-face CSS rules. You can check gfx.downloadable_fonts.enabled on the about:config page and make sure it is set to true (if necessary double-click the line to toggle its value to true). Also make sure you allow pages to choose their own fonts. *Options/Preferences -> General: Fonts & Colors -> Advanced
[X] "Allow pages to choose their own fonts, instead of my selections above" You can check the Web Console for font related messages.

• "3-bar" menu button or Tools -> Web Developer

That fixed it for me, thank you! You're awesome!