You’re digging the knife into the pit to get a grip on it without damaging the avocado flesh around it.

To do so, place the knife as shown in the picture, then hit the back of it with your hand to drive it in. I usually just take a swing at it with the knife itself, but it’s probably a little more consistent to do it this way.

Avocado pits are slippery. You can’t usually just grab them with your fingers.

So just do what the picture shows, and then do what the instructions say, in that order.