The difference from the google analytics icon and all the other icons is that background-image is placed within "Inline style" css that overrides

INPUT.epi-cmsButton-tools

We had the same issue, and in our case it turned out not to be a problem with EPiServer, or even Internet explorer but with the graphics card driver.

The icons come form a css sprite that is very tall: 8864px high. When using GPU accelerated rendering in IE10+ some machines cannot render it.

To see if you have the same problem, I've constructed a minimal example that shows the problem: http://julmas.se/large-images/

If you have the same problem, you will see a good image on the left (8191px tall) and a corrupt image on the right (8193px tall). This probably happens because the graphics card has a max texture size of 8192px.

You can fix the issue on your particular machine by going to "internet Options" in IE. Then the advanced settings tab. Here you need to turn of GPU acceleration. That is done by checking the box that says something like "Use software rendering instead of GPU rendering".

You then need to close all active windows and restart IE for the images to reappear.

Interestingly, Adobe photoshop refuses to save a jpeg image that is taller than 8192px. It's like they knew!

Thanks for your reply Markus!

That's interesting. I had a workshop with Episerver support to try to solve this issue on one of my computers. 

The result from this workshop was that I got a new ie.browser files from whom I talked with in Episerver support which I replaced on my client computer.

I have some customers that still have this problem. I will forward this information to them and see if it helps.

Thanks again, Markus! :)