Well here's a solution!
(yeah, I don't buy it either. That cat is looking at it as if to judge if it can make it and the answer would be "yes"
You're right: that is definitely not an expression of "impressed" on the cat's face ... it is very much an expression of calculation (distance x leaping power = tree comes crashing down onto the floor).
Last time I got a live tree I had six cats and I thought I was going to have to nail it to the wall.
Planned to get one this year but it didn't work out, alas.