Most fortune-telling builds I have seen run a crank or axle straight into the tray, so the linkage is either on display or masked with panels. This wizard skips that approach entirely. The 8-ball pointer turns with no mechanical connection to the body at all, and in my view that absence of visible linkage is what sells the magic.
The drive is hidden in the finished model but easy to follow once demonstrated. A yellow gear knob on the wizard's back takes the input. Inside, four small magnets form a coupling between an internal gear and the 8-ball, passing rotation across an air gap the way a compass needle follows. The drive sits upside down in the torso directly beneath the tray. On a grey demonstration plate, the maker shows a gear turning a shaft tipped with two disc magnets held in a clip, facing a matching pair on a rotating pin across the gap. In the digital instructions, this drive appears as assembly step 95.
The tray carries tiles reading YES, NO, ? and LEGO around the pointer, and the sticker work comes out looking close to printed. The maker is very happy with that result and plans a separate video on the sticker technique.
Fitting hidden technic functions into so small a space sounds like the hardest part of this, and the maker clearly enjoyed that challenge. The finished model keeps everything out of sight, so in my opinion the demonstration assembly on the grey plate does valuable explanatory work.