I like this one too… but yes you’re right. It’s generally called the ankle distraction. I tend to ‘scour around’ as he says and do lots of ankle rotation/movement whilst doing this. I find having the ankle up on a bench gives a very different effect.
Try it in combination with flexing the toes first, ensuring the arch doesn’t collapse then rocking forward into dorsi-flexion, this gives a nice similarity to walking and other activities that activate the flexors of the toes (and maybe arch too) whilst simultaneously needing ankle dorsi-flexion.