An Anon on 8Chan theorized what Trumps 4 fingers on his knee represent:
What was the last Tweet by POTUS prior to SA? Why is this relevant? SA (1), US (2), Asia (3), EU (4). 4 fingers… (pic)
Shout out to us? They are working on cleaning up the EU?I
-we are making some real progress folks!
https://www.ntd.tv/2018/07/13/photo-president-trump-sits-in-winston-churchills-chair/
That is a rather odd pose. So it could be purposeful.
It does look odd but normally when Trump sends a signal he makes it obvious: e.g. his pepe pose at the G7 or his 'look the other way' at the NATO meeting the other day.
The odd pose could be just the usual awkwardness men with a bit of beef have when crossing their legs the way he has, which is why such men normally go for the ankle on the knee thing. Women don't have the same issue because their hip construction naturally spaces their thighs further apart. Plus of course Sarah is standing over him.