Claire Bear

Hi There, I have started out sourcing some editing. I have just received a batch back that has in varying degress, has small grey squares scattered across at the top of the image on the white background. they are only pretty faint but i noticed them straight away. The person editing can not see them on his screen? do you have any idea what it might be pls? I have included here one of the images and also one that i heavily contrasted so that the pattern would become more obviouse Thanks !