Nautilus doesn't show some particular artwork

[Kamil_]

I want all my files to have embedded album covers. I tried using EasyTag, adding artwork inside file work BUT nautilus doesn't show it. I tried few other possibilities and results are follows:
What I noticed using iTunes, EasyTag, and couple of windows artwork tools:
* when adding artwork from iTunes, mp3 icons in Nautilus are replaced by embedded artwork
* it does not happen when using EasyTag and any other windows tool
* it does not depends on ID tag version, I have two mp3 with the same ID tag version, both of them have artwork inside and only one of them is displayed by nautilus.
Somebody could light me up how add artwork and force nautilus to show it? Or some hint how nautilus read inside artwork?

Thanks for reading!