The reconfigurable features of the panels makes them the ideal as puzzle elements. Many Multitasking Arms holding the panels appear to have a mind of their own, as they will juggle Weighted Storage Cubes, or slam against their frames out of frustration, even trying to get into their proper position by sliding back like snakes. For instance, when a panel moves around before Chell's eyes, or panels blocking her way moving into its position on a grid to allow the Test Subject to continue. Unlike in Portal, the backstage of a test chamber contains robotic arms and holds the back frames of the walls and floors of the testing area, with the mechanics and structures of the test chambers revealed. The panels are now supported by robotic arms, which were retconned into the game as a common variety and replacement of the pistons, which were still used within the cooperative campaign. The panels play a much larger role in the sequel than it did in the first game. Many areas within the Escape chapter reveals more of a test chamber's exterior, where the back frames are in their position but often lacking a piston to be configured, while the other back frames are held. The room revealed that the back frames of the panels were supported by pistons and that the pistons would need to be deployed by GLaDOS if she is to reconfigure these walls. The panels were first seen to be major reconfigurable platforms in Test Chamber 14, where a floor would randomly rise itself to form a staircase for Chell.Д®ventually in Test Chamber 16, Chell discovers the backstage of a test chamber where she is first introduced to the murals by Doug Rattmann stating that 'The Cake Is A Lie'.

Operated by hidden robotic arms or pistons, they can quickly form a new test chamber or adjust their configuration depending on player activity (for instance, the player can trap themselves in an area and a panel will open to allow them to escape). Whilst they are seemingly static, serving only as the bounds of a test chamber, they can also become dynamic, reconfigurable surfaces. They are generally either black or white tiled, indicating non-portalable and portalable surfaces respectively. Panels form the walls and floors of test chambers, observation rooms, and offices in the Enrichment Center.

Portal test chamber 15