I would expect there are people who lovingly care for their collection of vinyl records and find the desire to digitize a music collection equally unimaginable.
Granted, though I think the difference is even more pronounced when the primary purpose of the physical object is to be appreciated visually. Not to detract from the visual appeal of record sleeves, but the primary goal is to house the album.
I would also argue that sound can be reproduced digitally in a way that closely resembles the analog equivalent, but the same is not true of displaying art on screens vs on actual paper/canvas (despite the impressive efforts in the linked post).
Paint on any medium is a slightly sculptural 3D. You can look at a masterpiece from four hundred years ago and see the brushstrokes. The reflection from the relief map changes as you move your head.
Fine art inkjet prints are more subtly textured, because museum-grade paper is never perfectly flat.
A lot of art is huge - many feet by many feet. The giant displays needed to reproduce it don't exist yet.
But the biggest problem with electronic frames is working out how to power them without trailing an obvious power lead to the floor. You can solve this problem by plastering the display into the wall, or by building a false wall, or by ignoring it. None of those are ideal.
I'd love to see a practical solution, but I'm not sure one is possible with current technology - although it may get closer with the new film displays that are appearing.
I like the light sensing here though. That's a clever solution.