Comment by IAmEveryone

I was given a Sony camera to take photos at an event recently.

After two days, I noticed that the viewfinder would be dark when I turned the camera off. This was different than my usual Canon, so I wondered why.

Turns out it was a mirrorless camera, where the viewfinder is a screen. And I didn't notice that I was looking at a screen the whole time.

Edit: this was a Sony Alpha 7c. I really enjoyed using it. It's comfortably small and has the silver retro design of something from the 1930s.