I agree with you here but the hang up I keep going back to is that the finish on the wood under the pen is worn or damaged.
If this is an antique surface it makes sense but it wouldn't make sense that a worn piece of furniture is in a VIP cottage at CD.
I haven't found any references to antique furniture at CD that would be a match bit I'll keep digging.
The wood under the pen sure looks like the wood on the piano in the Holly Cabin at CD.
So "Note the desk" is possibly a play on words for the desk being the piano.
If this is correct the pen potentially belongs to Q and he uses it as a reference in images he shares here.
Today the pen sure looks like it was at CD.
Camp David is 62 miles from The White House.
Flight restrictions are in place when POTOS is at CD.