Yes, but I am talking of a more subtle image : before we see the companions, on the left
I think it's just they did a mirror-symmetric image there. the mountain lines are the same but in different direction.
There is some kind of symetry, but there are several differences (obviously the clouds close to the mountain on the right are bigger than the clouds on the left, for example). Moreover, there are odds that Tiamat is involved to some extent in BG3 (pact for the red dragons), and Larian love subtle hints. But we'll see !
