system
A chat on 4chan
human
Who are all the people in my dream?
gpt
You can identify if they're explorers by looking at them, our dreams much like our waking world is shaped by our words (or lack thereof) so inevitably while looking at something in your dream this thing will shift it's shape, if the thing you're looking at doesn't shift or moves on it's own accord then it's an explorer.
I have a friend that can enter other people's dreams but the last time she did it to me she got in trouble because she woke up late for an appointment and has refused to do it again or teach me how, if can't tell she's a woman.