Am I just imaginging a cow or is the cow actually here?
The setting of the Energy Planet is described "grasslike" so when Sam first sees the grass scenery he thinks there aren't any cows then a smoke appears and forms a cow.
What are you?
We sent someone out to watch you, we saw you talking to something and there was nothing there
The Energy Planet is causing conflict because Sam isn't suppose to be seeing hallucinations and now he is seeing a figure that looks like him.
You were experiencing a hallucination Sam!
When Sam goes back into the dome and Dr. Gentry starts asking him questions about what he saw Sam responds honestly. When Sam responds to Gentry he doesn't believe him so Sam and Gentry start to get into an argument about what Sam saw.