When episode 7 aired we interpreted this scene as Jax missing Ribbit and Kaufmo. That's still the case with episode 9's backstory but there's more to it.

This was after his fight with Pomni, and it forced him to dredge up old memories and trauma that he'd been supressing ever since his friends abstracted.

The turned-over photographs are another visual representation of Jax's suppression and dissociation. He pretended he didn't care Ribbit and Kaufmo abstracted, and deluded himself with 'All of this isn't real, so what does it matter' to try and get rid of that guilt. But there's still part of him that loved his friends, so the photos were never thrown away.

So at his lowest point Jax turned one face-up. Jax looking at this photo was him acknowledging Ribbit and Kaufmo's existence since they absracted. This was him letting all his repressed feelings out.

And that was probably too much for him because he started seeing Ribbit in the flesh? I guess that was the moment his mind started spiraling. And you know he was spiraling because he was reaching his hand to Ribbit, something he didn't do when she was still alive.

Jax living through all of that and thinking why hasn't he abstracted by now, and it was because of sheer force of repression and dissociation. And the second he opened that door, the second he connected to Ribbit, he was (almost) gone.