Additional Info
This hologram technically exists in datamining in the files but does not actually exist in-game. It is listed as being added to the game’s files in Patch 4.7.3.
TOR Decorating had it listed as “Source: Oppressor Alliance Pack / Stronghold Decoration: Technological – Machines / Hook Type: Centerpiece / Cost for Guild Stronghold Purchase: 75,000” and showed it as a yellow glowing hologram, but it was likely a datamined image rather than from in-game.