I am not a cactus expert but from a plant grower and landscpaper I have an idea. Many genetic mutations will try to revert back to the natural form. My guess is that in nature an easter cactus would look like this offshoot and it is reverting.
For me this kind of thing is nothing new I have seen this in several mutations and most commonly seen would be the needle point holly. It is a mutation that has only one point on the tip of the leaf. It will mutate back spontaniously and get the wild form of leaf. When that piece gets bigger I would break it off and keep it as a seprerate plant. I have a mutant canna variety that reverted back and I have been growing the revert as a new plant.

It IS reverting, like martenfisher suggested, but to what seems a more juvenile form, rather than its natural form (it's not a mutation, after all, unless you count the colour of its flowers).

This page has some talk about the phenomenon. I'm not sure the terms used there are all legitimate, but undoubtedly there's a scientific explanation and term for it somewhere. The page gives a good description, though, and I've seen similar growth on several of my epiphytic cacti in the few years I've kept them. It does seem to happen when they've been stressed, but that's anecdotal on my part. Either way, it's kind of interesting and the growth itself isn't harmful.

Wow, that is so weird. Thank you both. :) I guess I'll keep a close eye on it and see what it does. They're both pretty miniature right now.