I don't think so. The tats still on the same place. Look again. He was lying flat on the first scene. And the second one has his back on the bed.
It's different between chapters not panels.
I saw it too ! xD I was like "where did it go ??"
Nope, checked it two times, you look again. Page 7 chap. 8 tatoo is on his right hip (the scene where he out after shower), while page 7 chap. 9, sure he is flat on his back on the bed but his right side is tatooless and on the next the next page (p. 8 chap 9) the tatoo is on his left hip.
Compare:
http://www.mangago.zone/read-manga/cover_up/hs/mpn_chapter-2128590/pg-7/
and
http://www.mangago.zone/read-manga/cover_up/hs/mpn_chapter-2128588/pg-7/ (should be but it's not there) and it is here
http://www.mangago.zone/read-manga/cover_up/hs/mpn_chapter-2128588/pg-8/
more clearly visible here thou
http://www.mangago.zone/read-manga/cover_up/hs/mpn_chapter-2128588/pg-10/
Yeah. I got your point. Checked it again. I didn't think of it the last time coz I was thinking it's his reflection in the mirror. haiizz..
its moving (⊙…⊙ ). That colourful tatoo was on Geumhwa's right hip in chapter 8 but in chapter 9 it moved to his left hip.