Is this attached to the plant in the background?
I used to see "stolonous" type growth fairly frequently in barbatat types (which includes sangii), and we used to think it might have something to do with there habit of growing in leaf litter, where they grow on stolons to keep from getting burried.
Another theory was that the substrate is not to the liking of the roots so the plant is trying to "climb out" of the substrate.
Since going to low K feeding, I'm not seeing stolonous growth in barbarta any more, and older growths (pre low K feeding) that are on the ends of long stems are producing roots that are going into the substrate. So it seemed to me that these climbing plants were having problems with the substrate rather than some natural inclination to climb.
Seeing similar effects with Phrag besseae which have a reputation for climbing out of the pot.