In Mark 8:22-24, the blind man says, "I see people; they look like trees walking around."
Why is this different from all the other healings of the blind? Why did it take Jesus two times to heal this man? And why did people look like trees? Is this related to the harvest connotations in Revelation? I imagine in the energy emanating from our physical bodies as shown in one documentary: is that it? --Jon-Jon (Sydney)

You have hit on a major theme in Mark... Why did it take two goes before the man "got it," before he could "see"?  Because he is like you and me. We do not get it the first time we are told.  Now look at Jesus' disciples as portrayed in Mark. How often they fail to see the truth!  Especially about the nature of Jesus' messiahship: suffering and service. I would read all of Mark 8-10 and notice how the passage functions in this broader context.

Anyway, this has nothing to do with Revelation. As for people looking like trees, this comment merely illustrates that they saw only generally or broadly, but not accurately or with real perception. (Again, just like you and me!)