I took this video when I went for vacation in spain back in december 2021 (the exact date of the clip is 8 dec 2021). So I was admiring the scenery outside the window when I saw this strange mark on the glass, and it's pretty self-explanatory what it is LOL. A bird must have flown into the window and left that clear impression, and you can see its beak and wings and all. Thought it'd be pretty interesting to share. I also just posted it on my tiktok account.