Moqorro Is Using A Glamor But Why?

Moqorro is the red priest sent to meet Daenerys by the red temple in Volantis. He travels with Tyrion until he is washed overboard by a storm only to be picked up by Victarion Greyjoy after 10 days adrift at sea. His tattoos however seem to have changed slightly between his time with Tyrion and meeting Victarion. Also his appearance seems to shift as Victarion looks at him. These little hints seem to tell us he is using a glamor, which is a tool we have seen Melisandre using as well. She reveals how the power works in the same book we meet Moqorro. So what is going on with this red priest's glamor use and what is it hinting at?