They are the typical gates and windows of Nefta. The amounts of the gates are manufactured starting from the wood of apricot tree, drink very resistant and widespread in all Jérid. The slats are made of wood of palm tree. To treat them against the mites and mushrooms, the ancestors deposited the trunks of palm trees during several months in the chott (salted lake), before any use. 
You will notice that each gate has three stops, each one has a particular sonority and thus the Master or the housewife can recognize if it is about the visit of a woman, a man or a child. These stops are laid out of a certain manner: the stop for man is on the rising right, that of the woman on the left amount and that of the child, smaller, on the right amount but definitely low than the others.