I've noticed that the arena will change and become damaged after Gaia uses Guardian's Judgement in Phase 2. I think this is purely cosmetic, but I feel that it should be tested before it's added to the trivia.
Topic on Talk:Shrine of the Two-Headed Serpent
From Elwiki
Quick look at YouTube videos, you're right, added to Trivia. Feel free to add it yourself if you find things such as this.