I have a bunch of binos that I use about 50/50 terrestrial and on the night sky. For years I was only terrestrial, and have found it easy to think of terrestrial magnification like this:
Say my bino is 7x and I am looking at a target 7 miles away. Then I see that target, compared to my naked eye, 7 times bigger. Or (I like this one better) that target seems instead of 7 miles distant, only 1 mile.
But I have difficulty conceptualizing astronomical magnification in a down-to-earth way that my brain can intuit. Take Rigel, distance in light years ~1400. Since we want our binocular view of stars, at all magnifications, to be as pinpoints, it makes no sense to achieve a 7 times bigger pinpoint. And it seems not very helpful to say that a 7x bino lets you see Rigel as if distant only 200 light years. That’s not like viewing a 7-mile distant mountain, then walking 6 miles closer to see it from 1 mile ... or saving the walk and using a 7x bino.
On earth it makes sense (to me) to think of magnification as bigger or closer. On the night sky, probably it makes sense to think of binocular magnification as brighter, as in we can see stars of lesser magnitude, or any given star takes on a brighter magnitude—say at 7x Rigel goes from apparent mag ~.12 to ~.017. I guess that’s okay. Except just as bigger and closer don’t help in thinking about astro magnification, brighter doesn’t translate to terrestrial magnification. It doesn’t make sense to think of that mountain as 7 times brighter.
I am okay with this much, don’t feel a need to seek therapy about it. Still, your thoughts most welcome.