Harry, the Calvin and Hobbs book says it all for the creation behind it. The creator named Clavin after a 16th century theologian who believed in predestination and Hobbs was based upon his own house cat's personality, who would barrel into his legs when he came home(sound vaguely familiar that one?
) His view point from Calvin(being alive) vs others(doll) is not to denote a separate fantasy, but that reality is a perspective of the viewer. This reps the observers effect applied to TT, reality shifts based upon you knowledge or lack of it.
So Calvin and Hobbs represent Harry and Mister(also Bob?) and the comic is from Harry directly. It's the cluebat time travel was there, not who left it, but the hidden meaning behind what was left!