Simberg, best known for his themes of Death, the Devil, and Youth, seems to grapple with notions concerning mortality, the very joy of breathing, and the ever present specter of decay. Although I at times feel uncomfortable with his very young and very nude young boys, they may very simply depict Innocence. I must remember to look at his painting through the prism of his culture.
What is very apparent is the wit in which he depicts themes that in less capable hands would have resorted to mere macabre cliche.
From the 1896 photo with his sister Blenda (which he snapped himself with a time release camera) I sense a charming joy that he seems unable to contain. That joy resurfaces time and again with his impish Devils and goofy depictions of somber Death. (https://babylonbaroque.wordpress.com/2011/05/15/hugo-simberg-dark-optimist/)