This is one of those items that most people outside of Japan don’t “get”. But anyone in Japan recognizes them as illuminated lamps that sit outside of ice cream shops selling soft serve ice cream in Japan.
Here’s a picture that someone on Reddit snapped while walking around Japan.
You can’t miss these, especially on a hot summer night. They’re about 3 feet tall and do an amazing job of luring you in to enjoy a refreshing cone.
Not surprisingly they're made in China these days. You can find a lot of manufacturers selling these on Alibaba. This listing seems to be from one of the better manufacturers as far as a match for what you see in Animal Crossing and what you'd see in Japan. Notice the "swirl" at the top of the ice cream, and its height of 95cm (about 3.1 feet).