I never saw that Burton Wonka film, so my consistent thought when looking at this card is that the Knave looks like Lewis Carroll's Mad Hatter. And I think that the dreamy, liquid pathway up into the sky and the psychedelic mushrooms enhance that feeling of Wonderland...
The Knave cards in this deck would correspond to the Pages or Princesses in other decks, and these usually signify a person or energy that's on the younger side, maybe less worldly, although I generally still think of them as being very bright, inquisitive, talented, and eager. This Knave actually seems a bit more experienced and mature to me than the usual Court Cards at this same level. In fact, his bearing and pose seem to be offering a welcome, an invitation to enter into this Wonderland, and an offer to show the viewer around, as the viewer has every right to be there and should feel at home in this surreal land, and this Hatter knows the place intimately.
I have my issues with this deck's LWB, but here I agree that the card seems to be speaking of a world full of possibilities. It seems like a really positive indicator that the querent has almost endless potential and opportunities spread out before them, and merely needs to choose from among them -- in this particular Wonderland, choosing something makes that something real...