Well, I have managed to find a much higher detail image of Quipus 58 B.
Unfortunately it does not help very much, but if you look at some of his other works, especially the piece Quipus 14 G-1 then perhaps we might be able to make some estimations about the structure of the element in 58 B.
Here is a smaller image of 14 G-1
The corner construct is different to that in the image in question, but at least we are able to see the general form of construction and perhaps use this information to make assumptions about the image in question - 58 B.
The cloth starts out perfectly flat and wrinkle free in the bottom right hand corner and progresses across the board to the 'knot' at the top left hand corner. We can see from 14 G-1 that the 'knot' has at least three functions.
First is to keep the cloth strip under tension.
The second is to change the structure of the cloth from a strip into a bundle.
The third is to hold the bunched end of the cloth up and away from the board into the third dimension. The shadowing shows clearly this stand off effect.
In 14 G-1, we can surmise that Eielson has taken the bunched cloth and twisted it, then he has 'laid up' a short length of two strand Z twist cord. You can see two twists of this two strand cord going to the left, then presumably turning down towards the board and I would make a guess that the end of this cord is held against the board by two turns of the twisted single strand cord that has been taken over the top of the board, presumably brought up through a hole, over the end of the double strand cord (trapping it in place against the board), again up and over the top of the board, down the back and up through another hole to make the second and final trap of the double cord before it also is taken over the top of the board to be presumably tucked under the loops at the back of the board.
Using such a construct, Eielson would have been able to elevate the bunched end of the cloth to nearly five diameters of single strand above the board to create the 3D stand off effect.
If this is how Eielson has made 14 G-1 and we presume that he has used a similar technique for the corner construction of 58 B, then we might be looking into the top of the entry point of the two strands into a vertical knot, tied in a short piece of two strand cord. I cannot tell what sort of knot he has tied but I would be very tempted to take a flight of fancy and guess that he has tied one of the 'Long knots' used by the Quipucamayocs to record information within their amazing devices.
I have read that the Quipucamayocs would take a single strand cord, middle it, twist it and lay it up into a double strand cord for use in the quipu. What the fibres are made of, their colour and thickness, the twist (left or right hand) and how and where it was fixed to the main cord are all presumed to hold information over and above the information contained within the knots later put into the cord itself.
I wonder what additional information Eielson is presenting to us in these constructions he has given us. Although these pieces do not look much like quipu, perhaps we should remember that those string artefacts were in fact records, and that today the Quechua translation for Windows XP uses the word Kipu for 'File' so it is reasonable to call these pieces Quipu, because they also contain information for us.
I have to admit to finding both 58 B and 14 G-1 most fascinating - I wonder what Eielson was thinking when he created them.
Derek