Explain this to me

Okay. You know, there are all kinds of posters at bus stops. There are also the local public transportation organization's (HSL/HRT here in Helsinki) own posters. This is a picture of a poster like that. It is okay, with all the logos/pictures/whatever of all kinds of things like, well, bus numbers, a bike, a boat, etc. related to transportation, which you can see there. But there is also one picture which I just can't work out. It's the one with pink background. What the ...... is happening there???? Seriously?? :O I've shown this to few people and they don't know either. Any good suggestions?

Geez.
Oh ok sure we've had some ideas, but those just don't quite fit the general subject of the poster's other pictures. You know.