Notice how handler 1 is pushed up a little bit. Handler 3 is pushed back in order to keep their defender out of the lane. Defender 7 is set up to stop the deep cut, but also follow under.
See how defender 3 can block the lane if handler 3 is pushed up. Completely cuts off the open throws for handler 2.
Offensive cutter 7 moves deep, but their defender is right with them. The stack moves up a bit.
Offensive cutter 7 moves under, but their defender is still with them. (Notice how all the cuts are "vertical." This means that if you extend the line of a cut, it is always pointing toward an endzone, not a sideline.) As soon as offense 7 plants/pivots to come under, offense 6 starts moving deep.
Offense cutter 7 makes breakside cut, they are still sprinting. Offense 6 comes under. Handler 2 now has two good throws. The short throw to offense 6 is easy and reliable, a good handler will also have the break throw to offense 7.
If 5 is winning the deep run, handler 2 has a third option, a curving deep pass to offense 5.
If none of this is working, handlers begin fake cuts while the stack reforms.
Handlers 1 and 3 make their real cuts (notice that these are STILL vertical cuts, toward endzones, not toward sidelines.) Handler 2 now has a great pass to handler 3 and a decent pass to handler 1. Notice how offensive cutter 5 respects the handler cut from 3 and gets back in the stack. 4 however continues running deep.
That way when this throw goes off...
Handler 3 has an unmarked deep throw opportunity to offense 4. If you go back to the beginning you'll notice that offense 4 (the person who sets the stack) doesn't seem like they'll get to do much. In reality, if they do their job, they will often get to receive the deep throw off the swing to handler 3.