Not sure of the correct description of the item, but it came from the collection of someone who worked in computer game publicity in the early 1990s and did a similar job for Channel 4's GamesMaster TV Programme (Channel 4 is a television channel in the UK). I believe the item was sent to magazines and TV shows to be used for promotional purposes.

Really unique piece of DMG Gameboy history!

Tracked ahipping with signature from the UK.