The stand-alone (one-color) piece is called Selkie Kisses. It depicts a child with her seal "mother" on a beach somewhere. They are spending time together as mother and child, although they look nothing alike. In Celtic folklore, the Seal People partner with humans and even start families with them. Eventually, the seal parent (usually a female who finds the seal skin her human husband hid from her to keep her on land) returns "home" to the sea, but she returns frequently to visit her children, who are half human and half Selkie.
Selkies have the power to grant wishes to humans, although using that ability can result in their being stranded in human form onshore, longing for the sea. The most frequently granted wish, as you might imagine, is the wish the children make to keep them at "home" on land.