One calm sunny day at the beach, the gulls bothered some people for food. They sniff out free grub easily, even if the grub is safe inside a car with the windows up. Visual cues are important too, as it seems like you only have to pretend to eat and the action of hand to mouth will be enough to elicit gull curiosity.
However, in they are not usually fooled for long, and in this case have decided to settle on the railings.Or on the beach.
There again there's always one or two who get overexcited and won't settle down for love or money.