Well yes, that is a Fell stitch - but - the person is sewing left handed - and sewing the pleats in a very odd direction. We usually sew by hand in the direction the pleats point. Sewing in this direction it makes it very hard to insure you are going through all four layers. In fact it looks like he is only sewing through three layers. This would be very weak and subject to distortion of the fabric and ultimately failure.

And the stitches this person is doing are going to be huge and will always be visible. The thread he is using is massive and he is not using a thimble so the motion is not smooth.

I would not call this a good example of pleat stitching.

But he is using the Fell stitch.