I was thinking about flying mounts recently.

When the weather is not cloudy and it's daytime, I think it would be fun to see an enter/exit message displayed in the room below where a flying mount is passing overhead.

Something simple and subtle such as a shadow arrives from above or leaves north, etc. Nothing important, but it would be a clever touch if possible to pull off.

I think we all love emotes, like your shadows across the ground thing. That's a really good idea. It would make total sence to be able to see that. Shadows can be different sizes depending on the mob. Even the npcs that move around up there could do it. Might get annoying if a few mobs stick in the same area though. But I'd like to see it too.