One of the least intuitive—but most important—methods of controlling image size is using the volume control. More volume, bigger image.
If I am playing an easy to identify instrument, like a vocal, I can tweak the volume level until the performer is exactly the right size for my imaginary human. So you'd think that I could then memorize the level number and always hit the exact right size, but you'd be incorrect. The size of the voice or instrument depends on the room, the environment, and the speakers.
For example. If I am sitting alone in Music Room Two listening to a track everything is just right at a predetermined level setting. If suddenly half the engineering department wanders in to listen, which used to happen a lot back in the days when we all got together in person, I would have to turn the level control up to compensate for all that extra damping.
I don't mean to minimize the importance of the engineering department by referring to them as "damping material", but in this case, it happens to be true. :)
The point is, image size, height, width, and depth are all dependent on a specific volume level on a particular track within a given set of circumstances. This means you have to know what you're listening for and be ready to make adjustments.
I wonder how we would measure that?
Maybe next I'll work on an image size-O-meter to keep the subjective naysayers happy.