I've sent this image to a couple of shop's representatives and they can offer no insight as to what this is and is for. I asked the shop selling it and they couldn't say what it is, either, but (of course) they iterated that it's part of the lens design and is nothign to be alarmed at.
Without any explination, and the fact that I've not seen this on any other lenses of this type, I'm definitely not buying it!
Still, if anyone sees this and can provide any insight, please do so.
WM