This is a representation from illustrator Arthur Rackam of Liath Luachra teaching Demne (the young Fionn) at a very early age.
It’s actually a visual representation of a scene from Macgnímartha Finn where Liath Luachra and the young Fionn chase other around a tree with a switch.
There are quite a few interesting and unknown elements associated both with the picture and to that scene, but I’ll cover those in Vóg at a later date.