Leftmost figure
At the right of it
Mini sitting Ai figurine

• post #6184715 - Leftmost poster
• post #5890949 - Center poster
• Rightmost one looks like the outfit from post #6358968, but I can't quite fnd the actual source right now.

The manga next to the tower PC is volume 1 with a variation of post #5890906 on the cover, based on where in the book they are either the green or the pink bookmarks are on the page where Ai gets stabbed.

As for the mangas on the right:

• White spine, pink text: Volume 2
• White spine, blue text: Volume 3
• Black spine, blue text: Volume 5
• Black spine, pink text: Volume 6

EDIT:
Found some merch with the rightmost image

星野アイ said:

• Rightmost one looks like the outfit from post #6358968, but I can't quite fnd the actual source right now.

EDIT:
Found some merch with the rightmost image

I think the original source is the anime, episode 4 around 13:30-40, as B-roll when Kaburagi is describing his past interaction with Ai. The corresponding manga scene in chapter 18 doesn't have a frame like that.

In universe it's a shot for a fashion magazine.

Super_Affection said:

I think the original source is the anime, episode 4 around 13:30-40, as B-roll when Kaburagi is describing his past interaction with Ai. The corresponding manga scene in chapter 18 doesn't have a frame like that.

In universe it's a shot for a fashion magazine.

Nicely spotted, that explains it.