I was in Japan a month ago and these are everywhere! Pretty much every where I went (esp in Tokyo), they're in front of the restaurant.
After awhile, you'll notice they don't vary too much one to the other. But it's still a fascinating UX. I'm used to looking up photos on Yelp and yet I still found myself looking closely at...plastic!
It's basically the equivalent of clothed mannequin displays for boutiques and shops.
People are window shopping a lot of Japan for their food options, oweing to the very high walkability, density of shops esp inside department stores and airports and the like, and high overall average quality of shops where very rarely will you have a terrible experience, making people more willing to step into ships with very little prior vetting. So when your customers are window shopping, these serve to tempt and posture their interest to step foot in the store. When you see the udon bowl you might think "oh I didn't realize it until now, but I'm in the mood for udon today".
> making people more willing to step into shops with very little prior vetting
After eleven years in Japan, it works the other way around for me too; if there are no plastic samples out front, I'll just mentally dismiss restaurant and keep looking for somewhere else.
Even the restaurants that can't afford plastic samples for whatever reason will often make popular/common dishes and just saran wrap them to put them outside to show what's on the menu.
There is an excellent scene in Wim Wenders Tokyo Ga[0] showing wax food being made in Tokyo in the 80's. The scene itself is incredibly therapeutic to watch for some reason. But that could be Wim's filming style.
Nothing to do with Japan, but there is a very fun Wonderfood museum in Penang, Malaysia. It has lots of incredibly realistic fake food. I was looking at the plastic things up close and still found it difficult to believe it was fake. :)
Ended up in there by chance when I looked for a escape on a brutally hot day. Wonderful unique experience. And the staff is eager to explain every little detail which was a nice add on as lost solo traveller.
After awhile, you'll notice they don't vary too much one to the other. But it's still a fascinating UX. I'm used to looking up photos on Yelp and yet I still found myself looking closely at...plastic!