Reverse painting is when you paint on the backside of plexiglass, acrylic panel or glass. Since you are looking through the clear panel, you build up the painting backwards & flip-flopped. So the for most marks (like the black ones in this painting) are actually made first. First photo is it against wood, the second is when you have a light source behind it.
Jessica R. Willis
Artist of many mediums inspired by nature and philanthropy