This paper investigates the playful photo taking behaviour of teenagers during group visits to two touristic public events (an airshow and a guided tour of a museum). These studies provide the feedback for the iterative development of a smartphone based anonymous image annotation and sharing application. The resulting implications for the design of such photo systems are examined, specifically the appropriateness of opportunistic upload for social media. Playfulness in photography has many implications regarding wider social behaviours. Comic annotations provide the ability to create humorous reinterpretations of photos, and the presence of humour and in-jokes affect the makeup of the audience with whom a group would like to share. It is counter-productive that an application encouraging such limiting behaviours may conflict with the open nature of touristic events. In addition, the shared images have an ephemeral quality and are therefore of transient value (compared to more tangible souvenirs), and their production through the application can ultimately distract from the experience of the visit itself.