These people were waiting for the wooden decked swing bridge at Moll d'Espanya to close again after letting boats sail into the marina. The wooden platform and the path along the bridge towards Maremagnum, the big leisure center, is called Rambla de Mar. The bridge was designed by Albert Viaplana, professor of Architectural Project at the School of Architecture of Barcelona University and Helio Piñon, his partner, teaching at the school since 1970 and co-editor of Arquitecturas-bis since 1974. They are responsible for major projects in the city so I suggest you check their work here Viaplana & Piñon. Here is a Google Earth Map with a view of the bridge at Rambla de Mar and Maremagnum.
