Not to say violins not made with these qualities are not nice, but I’ve noticed alot of the nicer violins often have beautiful wood patterns and grains, especially along the back, and the purfling is actually inlaid and not just painted on.
More than looks though, I think the tone of the instrument is what a big part of quality. And that is often personal preference.
I love “window shopping” online at goodwill just to see the variety. There are tons of cheap made in China ones, but there every once in a while there happens to be a beautiful old instrument in a beat up case…I’d love to know its story.