This is the Barrow Mall on the first floor of the Victoria Wharf Shopping Centre at the V&A Waterfront. At these barrows you can buy anything from pet's clothing to jewellery, and from sporting merchandise to mugs. This is presumably a slightly cheaper option for retailers, offering them a space to sell their products at a very popular mall, but without the high costs associated with renting an actual shop. Of course, it means they miss out on some of the luxuries of a shop too, like, say, a door...
As someone who used to sell products at a craft market, I think it would be awesome if these barrows were actual trailers that could be towed behind a car - you'd be able to sell your products anywhere you liked, without having to pack and unpack every time. Of course, with the way I take corners in my car, I'd have to tape everything down with duct tape, or stick to selling soft, non-breakable items like cushions. ;-)