US Rosalia Martinez is taking a break. A Mexico-born legal resident of the US, she and her friends live in Tijuana and cross the border into California every day to help travellers carry their bags.
It is tiring work, made worse by the searing midday heat, so Ms Martinez has found a step in the shade on which to sit. Fanning herself with a magazine, she says she has noticed an increase in the number of Mexicans coming home from the US.
