Hub Monitor
I was wondering how to get the image from the monitors in the coop hub. The ones that help you control which level you want to pick. I don't know where to get the image on the monitor.
Mapping Since May 21, 2011
The level choosers are a mix of entities and scripts which toggles different entities (and vgui screens. Also skins - like the buttons). Noticeably, the coop_transition script is used to set what level it will change to when both players are in the disassemblers, also to decide which map is the start or end of the campaign so it can tell it to make the correct arrow 'greyed out'.
Decompiling would be the key here and you can also find out what scripts are executed so you can edit them to your liking. However it would be good to have a working model/instance of this for people who want to create a hub-style map. I may work on this in the near future.
well I really want to get it to work, so I guess I'll go figure out how to decompile a map, and work from there. need a depressed icon here... i guess this works 
Mapping Since May 21, 2011
Looking through this, there is no specific way to change the name of the course on the vgui screen or the text that is shown without actually changing the language text inside the Portal2 English txt. This is because it is done through a console command.
I will be looking further into this.