Is the eye a reference to the Burrower Below from Fallen London, or the artist's take on the Foam Eyed Queen?
It's the eye seen on the Fire Giant's chest. The Black Flame is derived from the Flame of Ruin worshipped by the Fire Giants. Melina's eye is sealed and since it's a common theory that she is the Gloam Eyed Queen the artist gave her the same eye. Also, since Marika is talking here about nightmares, the Fire incantations used by the Prophets are derived from the Fire Giant's Incantations and their lore is that they received visions of the Erdtree burning down this would be another connection.
