Is it possible that is part of the guts from a bluetooth earpiece? I only wonder due to the "HS-105" being listed for various headset device model numbers...
Have you scanned it to see if it is transmitting RF? Have you identified a power source on it?
The upper pic appears to show 10 rectangular openings in the pcb, each containing a component. Could those be battery cells? Or lumped inductors/caps forming an antenna?
It seems like a mic from a headset. the button suggests this.
Also there are "R" and "L" letters printed on the pcb, further suggesting Right and Left Earphone wiring
There doesnt appear to be a power source.
Above comment on it being an earpiece makes sense, I think someones having a laugh.
Is there any reason someone would want to bug your desk, or play a trick making you think that?
i also vote asset ID tag because we have a desk here from dads old office at the uni he worked part time and it has something like that glued under it with a label saying asset no blah blah blah