A quick and fairly odd one, this.
I found an old ink cartridge for a printer lying around. I stuck it to a plasticard base and added some odds and ends from the bits box, including a TT Combat resin computer terminal, a spare base and a sigmarine shield.
Then it got some paint.
I think it's some kind of generator, which is my default answer to explain strange bits of tech like this. The posters came from a printable sheet that was on the Games Workshop website for a while.