Brevity and randomness
Sometimes I'll be dreaming or just sleeping and a vision will kind of flash through my mind. Just a couple of seconds. It seems completely random and, if I'm dreaming, unrelated.
Empathy
For me, this is a big one but I'm not sure if everyone has their visions the same. I tend to sense what the person(s) I'm seeing is feeling. Whether it be an emotion, a smell, a taste or a physical pain.
Dream disruption
Awaking after the flash, feeling like you have been startled out of your sleep.
Would love to hear about the experiences of others

Blessed Be