In Deus Ex you can see screens hanging at the walls. Or let’s say they’re electrical boards. If you get near to them, you can see weird artifacts. It’s like in Matrix where Neo gets questioned by the police, sitting in a small room. First you see that through a monitor but the viewers “eye” (camera) gets closer and closer until we “enter” the screen and are in the room with Neo. Shortly before this you can see very similar artifacts there also. Now we know how this lady from The Ring feels.
Source: Deus Ex
I assume that there screen/board shader was supporting two texture layers. First there would be the texture map of the map and than a really extreme tiled small detail map.