For me a hard refresh (SHIFT + Reload) of the page worked! The gray rectangle is gone.

Hello utopie, I am just facing the same issue. I have developed an app for a popular political german news blog. I have their explicit permission to develop it and take their icons and so on for it. I was also rejected with the reference to Guideline 4.1 Copycats. Were you able to solve the problem? Thank you in advamce!