Yeah, Standby comes on when I have it plugged in and horizontal. It only shows for about 20 seconds for me on iPhone 12 before it fades out to a black screen. I can wave my hand for it to come back shortly for another 20 seconds or so. I’d like it as a bedside clock more if it stayed on longer.
From what I’ve read, there’s an Always On function in settings for iPhone 14 that doesn’t seem to be available for older phones