We typically think of Yelp reviews as aggregates on a restaurant or business-specific level. Search for restaurants on Yelp, and you have an overall rating for each result. But zoom out a level and aggregate over geographic areas instead of specific locations, and you get a better idea of the makeup of a city. This is what the Yelp Word Map provides.
The Yelp Word Map shows where words such as hipster, pasta, and dim sum, are used in reviews, so you end up with a visual of where the pockets in a city are.