Something I love in HD transfers of old animation: seeing little details like the shadows the paintings on the cel cast on the lower layers. https://awoo.space/media/aXY_nvIsv9B1fF82CL0
Lum is on the top layer in this shot, and if you look closely around her head you can see the cel's casting a shadow on the background!

@dog mmm yes 🙂

I remember seeing something like this in the OP on the Blu-Ray release of Nadesico; you could see a cutout outline of the Nadesico against the stars. Super nice.