No problem with resurrecting a thread, especially when it provides useful information! I've actually been looking to put a name to the paired jo exercises where partners mirror each others movements. Looks like this is it.
Youtube gives a few hits for "jo kagame". These appear to be mostly by user "aikido abq" which I presume is Aikido of Albuquerque
. ("aikido abq" seems to enjoy posting class clips of his students, so instructional value of any given clip varies greatly)
seems to be dialectic and/or transliteration difference, but the dictionary form seems to be kagami
. By context, I'm guessing this is 鏡 "mirror", rather than 鑑/鑒 "model/pattern", but the second definition seems like it might fit, too.