Our natural bob tailed English Shepherd, Maggie has a much bigger "flight zone" established with the sheep simply because the sheep know they'll get nipped in the heels/butt if they don't move.
The first photo shows she's in a controlled mode. That is, she's not "chasing" after them and yet she's keeping the pressure on them to keep them moving forward towards the gate.
The second photo is after the sheep passed through the (first) gate and are now being moved through the second (gate). Maggie continues to keep just the right amount of pressure on them and with a little reminder from me, maintains a controlled speed.
In the the third photo, Maggie moves in a bit further as the sheep file into the barn. Again she's rating the amount of pressure needed to keep the sheep moving along.
The fourth and fifth photos Maggie is "watching the gate". She's giving the sheep the "eye of doom" in the 4th photo as if to say "Make My Day!". And once she sees the sheep settle, she too eases by taking her eye off them. However, she's still "on duty".