The gather is the part of the action that precedes the arm reaching up and out towards the batsman as you explode through the crease (4th from left). As you walk or run in, he suggests that if your action is going completely wrong and you've identified it's the gather that is the problem, you grab your ear until you're in position to the reach up and out (From the left that would be image 2 & 3 that would be the ear grabbing stage).
Maybe don't actually grab your ear, but get your hand up around your face and hold it there as you work through the issue.