A friend of mine posted a picture of these triangular drums on Facebook. The company is called "Delta Drum," apparently a French outfit. The general consensus was: what the fuck are they thinking?
Could there be a manufacturing advantage to the triangle thing? I doubt it. Do they have a particular sound? Could be, I suppose, but I don't have the critical faculties to make that judgment. Does the company just want to separate themselves from the other drum manufacturers? That could be the answer.
Or maybe they're just being French, in the typically "LOOK AT ME!" French kind of way. That's probably it.