I thought, wow, this can be a good lesbian fantasy, right? ;)
But actually this is one of illustrations for “The Ring of Nibelung” by Arthur Rackham (illustrator of “Alice in Wonderland”).
I recently bought Dulac’s Fairy Tale Illustrations in Full Color and just ordered a out-of-print biography, “Arthur Rackham”, from a seller in Malaysia (my favorite illustrator; can’t wait to receive it :D ).
By the way, some of works can be found in Project Gutenberg (especially Gustave Doré) but many still have copyrights in US so it’s illegal to download them in US.