Ah, yes, you’re right (and I might match you in
(dis)iorganization/findability of received mail, alas!).
It’s surprising that this seems to be a new knot, given that
it is so like [u]ABOK #1097, which treats the trio of paired
parts (the twin ends & two bights) as equals and gives each
the like relation to one of its neighbors --A is to B as B to C to A.
Even though their functions/loadings should be expected
to be not so equal.
One would expect someone to see the above point and look
to making A to B --speaking of the bights-- a reciprocal relation,
and the twin ends standing apart from this.
In any case, did I know of it? Yes, by my own fiddling. But,
how much knowing : only now in gazing at these images
does it occur to me that one can see this as the twin ends
pouring material into a (horizontally oriented, here) twin
piece (with bight ends) that then ties an overhand knot
around the twin ends!
And doing some theoretical playing on this notion, why not see
about instead tying a fig.8 or better a symmetric fig.9 knot(s) !?
The former has a different symmetry from the original & latter,
so doesn’t seem to offer a happy result; the latter gets bulky
without obvious advantage to that. --but it leads to some more,
interesting musings about knot construction.