Barcelona City Council launched a massive marketing campaign recently and the whole city was covered with these flags. The heartbeat logo may be useful for whatever plans L'Ajuntament schemes.
According to many, it is more a corporate logo than a symbol to help conveying an idea: it may be used for sports, the elders, transportation, the disabled, and so on but nobody really knows what the "heartbeat" really means.
It would be no big deal in the end if they had not spent 1.6 m € in the campaign. I hope at least you enjoyed the beautiful Casa Sayrach, a modernist building with tower back there which appeared also in this previous post.
See Picture of Modernist House with Tower on a Google Earth Map
