Dishes carry the traffic. A specific dumpling or bun gets searched by name, usually by somebody who ate it once and has been thinking about it since, and listing what the kitchen actually makes reaches them where a page about Chinese food never will.
First-timers search for instructions. What to order, how much and in what order is looked for by people about to try it, and a restaurant that answers becomes the one they try it at.
The searching happens on Saturday and Sunday morning. Weekend lunch is when this cuisine is eaten, so opening hours, whether booking is needed and how long the wait is are the entire decision.
Dietary questions are unusually frequent. What is vegetarian, what contains pork and what can be made without shellfish is asked constantly, and answering it in writing saves both the guest and the floor staff.