No way BIY takes that shit seriously I mean look at him, he just lost a cycle and hes happy as shit.
Season 1 Episode 4 when Victor has a flashback of him surviving the cycle while showing the faraway tree to Ethan.
Update: This ended up being nothing, just a texture pattern, leaving the post for historical reference in case somebody questions if this is part of the mystery. Photo in the comments.
Asset name: roa_rock_03
Coordinates on map: 5.224, -0.884, 1.858
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Original Post:
Chapter 6 mission "Icarus and Friends" you can see the carving in this video at 18:02 https://www.youtube.com/watch?v=NOc7CTrTFbQ . Location in the comments.