To the OP. I would get a microfiber cloth with some distilled water or led display cleaner without alcohol and very carefully rub the display where there is the marking. It looks like adhesive that can be removed. It may take a few times because the adhesive has cured and dried. A 70% rubbing alcohol diluted with the distilled water like a 50/50 ratio might help dissolve the adhesive. You should be able to remove it. It doesn't look like a scratch or something permanent. I hope you can remove it yourself!!