Everyone percieves others in dreams a bit differently. I agree that it's something that grabs your attention. Waking Nomad states that real dreamers are more stable and won't go away if you ignore them.

For me the person Completely Stands out from the dream. I always say it's like watching a black and white TV screen and suddenly a person in technicolor runs across the street. My dreams are often shady and very unstable, then a person shows up and they look more real and stable. you know? A lot of the times their face will be luminescent.