From Halopedia, the Halo wiki
The Corner is a chain of stores in the Mombasa area. It presumably dealt with food as it advertised it was "Local" and "Fresh".
The Corner maintained a stall in the West Market and a smaller kiosk on a floor of the Hope-Makupa interchange station.
The business was started in 2544. By the post-war era, at least two stores existed in the chain.
Concept art of the The Corner store on the Halo Infinite multiplayer map Bazaar.
More concept art of the store, exploring different color combinations.