i have two issues with this, one, it would be somewhere between hard and impossible for a bird shaped animal to land on something that small with a pole in the middle, and two, i'm doubtful that those six tiny columns would support all that weight. yes, things like that irritate me. other than that it's a nice picture, particularly the ribbon.
It's a cat shaped animal and a cat can stand on more precarious surfaces than that. Also worth noting is that you are questioning a narrative that doesn't exist. There is no evidence to suggest how the animal got up there (it could have climbed from the lower roof) so the point is moot. I would expect the wings to be clipping that pole however.
You would be surprised how much load a properly engineered pillar can support. [link]
The obvious critique for this piece is the fact that almost every ellipse is drawn at an arbitrary angle, yet every vertical surface is 90 degrees to the picture plane.
This is quite beautiful, I especially like the attention to detail with the shadows. Out of curiosity, are the wings one of the things that are bothering you? Their anatomy does look a little off - in fact, it looks like you had some anatomy difficulties with the griffin in general.
The saddle does look to be very well positioned, though, and the architecture is absolutely beautiful.