Slab
A bar set off the plate's center so the wall keeps more of the load. Weight is not centered. The edge is the argument. Nothing else is permitted to speak.
Void
The plate is plaster and the opening is the room behind it. You are not looking at a picture of absence. You are looking through, into the same concrete wall.
Temperature
Oxide lines lie tight across the plate, a register of heat without weather. Nothing depicts temperature. The density of the mark is the temperature, held flat against the cooler wall.
Repeat
Bolts set on a measured grid, each the same, none the center. Repetition is the structure, not a pattern for pleasure. Count them and the wall answers with more wall.