Train pop-up shop

Quick answer：

A pop-up shop, also known as a pop-up store, is a temporary retail location that is set up to sell products for a short period of time. A 'Train pop-up shop' could refer to a temporary retail kiosk or stall installed on a train, providing passengers with shopping opportunities during their journeys. This concept is often used for marketing purposes, to introduce new products, or to increase brand awareness. The train serves as a mobile platform, reaching a wide audience in various locations.