I only just realized while watching the Hadestown pro-shot why Hades was so insistent on showing his work to Persephone
“In the coldest time of year, why is it so hot down here?”
“In the darkest time of year, why is it so bright down here?”
He was trying to create summer in the Hadestown for her (and obviously for himself and his work, but you get the point)
He knows she loves the world above, and whenever she comes she brings summer and sun and the joys of life, so he was trying to create those same conditions in Hadestown, hoping she’d like it, appreciate what he was doing, and want to stay longer
It also probably reminded him of her, with her warmth and brightness gone when she’s above “lover you were gone so long, lover I was lonesome” “think of it as my desire for you”
He’s trying to artificially create some of the gifts and love she brings to the world above that she loves so much, but he’s not doing it just for her, and he can’t recreate the real world and replicate nature
“It ain’t right and it ain’t natural”
“Did you think I’d be impressed with this neon necropolis?”
Instead of it being a symbol of his love, to her it’s become a symbol of his obsession and his greed. He is trying to copy everything that comes from nature and Persephone’s presence as a goddess, but it’s almost a bastardization or mockery of her nature, recreated in a way he can control
He’s trying to impress her, but he’s unintentionally mocking her, creating a version of aspects of herself that he can control, and that he can use to fill the hole she leaves and that he can’t fill himself