Travellers in Europe and Britain have always been associated with a style tent called a bender. This comes from the construction technique of cutting saplings and bending them into a dome, elongated dome, or half cylinder shape, These frameworks were then covered with tarps and made watertight in the temperate damp. The origins of this design are lost in the mists of time and are believed by archaeologists to be one of the earliest style of recognizable tent structure used by humans.
Even after a certain level of affluence allowed some Romany and other Travelling folk to own living wagons, the bender continued (and continues) to be a way to extend the living space without the need for a lot more gear.
The fact that a tent becomes the subject for a Blackpool post card shows the ongoing fascination with “Gypsy Culture,” especially in the British Isles where Travellers are simultaneously suspect and romanticized.
If you have family that me be Romany, Traveller, or Fairground folk in Britain or just want to learn more, check out the Romany & Traveller Family History Society at http://rtfhs.org.uk/.