I have noticed phones with a handset (like the one in the image) have a little cover that resembles something like a cold camera shoe under the bottom of the handset’s top speaker holder. Is there a use for it? It has a line bump in the middle, but it doesn’t go all the way from both sides, it leaves a gap. I have also seem some of them have extra space on the top of the cover, and some don’t.
I would hazard a guess that
this is just a picture of a “telephone with a handset”, not the specific thing they’re talking about, and
their phone has a removable “hook” that was removed and lost sometime in the past and they’re seeing the slot where it went