Those were people making those mosaics, not machines.
We like to turn things into code (and "configuration languages", and package managers, and licenses, and...), why should mosaicists, if they're already spending all day picking and setting little bits of stone, not want to create images?
Love that first image - the ground movement has made it look like a piece of fabric.
Busy, but still harmonious. If I "step back" (eg the last image in the article), I don't get a sense of visual clutter, I get a sense of a coherent, balanced design. This, although from a later period, is a good example of what I'm getting at: https://en.wikipedia.org/wiki/Byzantine_mosaics#/media/File:...
Maybe it's something to do with the use of symmetry (I'm hoping a trained artist swings by and explains my own comment to me).
The little I know about contemporary mosaic[0] is about as busy. Perhaps even more, as we now have wider color palettes. Compared to contemporary architecture, yes, I'd agree though. But it's on par with contemporary fine-arts.
Worth keeping in mind the mosaics themselves are pretty large, and also indoor features typically illuminated by grease lamps or braziers, so you'd never see the whole thing all at once in bright electric lighting like we do today.
Ironically, our sort of monochrome minimalist white marble aesthetic owes itself to a misreading of Greeks and Roman design. The more we dig up, the more we find how colorful classical antiquity was.
But it's possible that, in the Roman era, with fewer forms of visual entertainment, these elaborate scenes served not just as decoration but as storytelling devices
