I finished the game but jeydon the friendly FBI agent dies by the origami killer.

The asshole who he worked with puts on his glass's to see jeydon in the ARI virtual reality. Why? And why was he so shocked to see him?

What was that entire scene about I'm so confused? Thanks

Well first off, you should include a spoiler warning in the title.
Secondly, it's because Jayden used ARI so much that when he died hypothetically he became one whom lived within the virtual reality.
It signifies that Jayden was addicted to using ARI and when his co worker put them on he noticed Jayden and therefore got startled.