and ABOK#787 is in the category ‘two-strand lanyard’ knots.
this video shows how a 3x4 ring mat is translated to a two-strand lanyard knot.
and it’s different from a button, which is terminal.
each end (colour) is brought around the standing part of the other colour to complete the knot,
which causes what seem to be extras in it all when examined.
i think that’s what you were looking at
(i had issues adding video or abok pic links so i split the reply)
i started with the Knot Book by Geoffrey Budworth,
a great general paperback