The biggest challenge in this particular variation is the fast-paced tempo and ornament execution–not to mention the fleeting 4 against 3 relationship of treble 32nds above 16ths in the bass. But the latter, should not be a big concern considering how quickly everything spins by.
In the video instruction I suggest a step-wise practicing routine where the left hand is blocked in groups of three, tracking common tones and those that move.
Fingering is very critical in playing Variation 2 smoothly, so I have attached my recommendations, subject to modification depending on what is easiest for the player. I don’t think finger choices are set in stone.
As to character, this variant has the droll dimension due to the dissonant 1/2-steps rolling through it in the bass, (the D#, E redundancy, for example) and the prominent 8th note half-step bass line grace notes which are fleshed out in Forte measures.
Variation 2 definitely reflects Mozart’s lighthearted personality.
REMINDER: Slow practicing is the gateway to a happy long-range result. (Re: the ornaments, practice them slowly, and start on the upper neighbor of principal note)
For some players, depending on level and ability, a turn will be adequate. For others, try for more repercussions.
Close-up view– no repeats–for supple wrist motion and relaxed elbow swing out…