It's apparently called Mexican pleating, which I've not heard of before. I've done a little searching (well typed it into google) and can't really find anything on Mexican pleating so it's likely to go by another name.
I think it's a quirky technique that could easily add a little interest to a plain dress, top, waist band or cushion even.
If you do give it a go, I'd love to see the results, I may even do a post show casing them!!
Hope you have a fab weekend!!