One reason could be that you have setup a contact in eM Client that has the Gmail address and black image as expected, but you have also included the informaticisenzafront… address in that contact’s details. Or you have the informaticisenzafront… address setup as its own contact with the black image manually selected as its avatar.
Another could be that you have a Gravatar account for the informaticisenzafront… address that has the black image as its avatar.
There might be other reasons. Maybe someone else has some ideas.