Originally posted by Bosse de Nage
What's with the multiple versions of himself?
That comes later, after he's been "smoking his J" for a while. He's starting to get intoxicated by then, and the second (and third, Dancin' Shatner), I think, is in his mind, which is why the sitting Shatner gets quiet and looks at the other Shatner...he's not talking any more, he's thinking.
Based on the lyrics, this is taking place in the wee hours of the morning, maybe three AM the night before he goes out in the rickety experimental contraption they're going to put him in.
The second Shatner seems to come in when the chorus comes on. I suspect the real Shatner's remembering himself say those words a few minutes ago and then twisting the image so he's standing or whatever in a muddled, fascinated haze.