I love the strong emotions in this picture. Typically the lioness is the one in charge, the one who hunts and takes care of the babies but here she surrenders, gives up her power momentarily to engage to the lion's sweet play.
"Course he isn't safe. But he's good. He's the King, I tell you. Beaver, answering one of the Pevensie children's question about whether or not the lion Aslan was safe (Aslan represents God in the allegorical series The Chronicles of Narnia)
Lions are nocturnal creatures, and are a symbol of authority and command over subconscious thought(as night is an ancient symbol of the subconscious - or dream states). The lion is considered by many ancient cultures to be a solar animal judgment.