In my case, I separate the folders on my NAS into lossy, lossless and a couple of other things. This is partly a legacy factor of how I've biult up my collection over the years, and partly because I like to have things organised that way. So the principal difference is that artist view aggregates everything together per artist.
I can then use minimserver to differentiate between quality ratings of files, i.e. I can browse only HD flies, CD quality or lower-than-CD quality without changing the folder structure on the NAS. I also have it set up so that a quality tag is added to album titles when browsing via artist view.
The upshot is that I can keep track of lossy vs lossless files on my NAS, but at the same time when I browse via artist view on the Naim app, I can select an artist and see everything I've got by them. And there are quality tags ([CD], [HD] etc) at the end of the album names.
A more basic difference is that when selecting an album via artist view, you get the artwork presented once at the top, with a track list underneath. With folder view, I believe you get repeated artwork tiles next to each track.
