Explanation:
if I interpret the graphic correctly, then there is a basin fully filled with water on the left, then a piece of paper of a piece of glass, where the paper is in contract with the water on the left, and some water is delivered to the right.
then i suspect this shows the capillary effect of very narrow channels of water. like in the very tiny spaces between the fibers of the paper. as long as the paper is in contact with the water on the left, and the level of water is there higher than on the right, the surface tension of water kind of propels itself further along these narrow channels in the paper and supported by gravity and air pressure it drops even into the other side.
