The video Damon shows

You can clear see an alien looking behind the branches.

Alien in the tree. Perhaps you should try some HOGs before watching again.

I love how it's a generic, owl face Alien too. It made me roll my eyes like 'oh ffs.. really?' Then when said Alien was never on screen and the ending is revealed, its pretty cool that the real Aliens used that as a way to immediately get Nick on board with the idea of Alien life and how they are typically perceived in media.