How to give a window reflection depth?


I’m trying to create this window reflection which looks good when the camera is far away but when it gets close it looks flat. Do you know how I can add depth to the reflection?


Is the reflected layer a single image or an animated (or recorded) footage?
Reflection works the same way like the reflected objects would be in front of the camera. So if the reflection is not changing in sync with the camera movement then it will not look look like a reflected 3D environment but a transparent photo sticker.
If you have to work with a single image, you should separate different parts of the picture to 3d cards to add parallax, render the fake environment with the 3D camera and use that for reflection.

For closeups duplicate the window reflection card and slightly offset it in Z, so the thickness of the glass can be seen.
Add different dirt layers (with very low opacity) to both sides.
You can play around with color correcting the duplicate reflection to give the glass some tint.

If the camera goes really close you can apply fake DOF.