Well, if you're happy (or not happy in my case) to watch the Star Wars Ep. So you might have some idea of what's going on in this set. Recall that BB-8 hijacked the Walker just to make Captain Phasma look worthless in the second Star Wars movie (even thinking about it gives me a headache).

But I'll keep my Ep. Because no matter how you look at the scene, it's hilarious to see Lego sell the walkers, or at least half of them.