Fingers as Smaller Flux Tubes at the Open End
Fingers. At the open end of a flux tube, flux stuff spills out and often there are smaller flux tubes that either form or emerge from inside.
Follow the green tube on image A, then blue, then purple, and notice that more than one smaller tube comes out (fingers). The same pattern on image B and E, which are worth a close look.
Image C has the sleeve fabric representing the barrier surrounding a flux tube, with crosslinked structure. The fingers are probably representing smaller flux tubes, and the pearls are showing perhaps some debris that is crosslinked.
Image D, F and G have weird disturbing fingers, but they make sense if they are showing what happens at the spilling end of flux tubes.