Art, grafitti or just rubbish?

There's plenty of concrete at Newcastle University where I work. There are also plenty of attractive red brick buildings, but i've only ever seen the concrete walls painted by undercover artists. (I like to think they're being respectful, but i'm sure flat, grey concrete makes a far better canvas!) There's a great batman silhouette and an amusing slogan underneath a CCTV camera (that perhaps i'll blip in the future).

This one appeared recently and I can't quite work it out. Is it the bin that's overly-large or the figure who's incredibly short?

What't the message? Any thoughts or interpretations from fellow blippers...?