Street Art? Or Clever Marketing Tool?

This wall painting recently appeared, apparently overnight, at both Marylebone Station in London and Moor Street Station in Birmingham. It depicts a character called Emmet from The Lego Movie, and is a pastiche of street artist Banksy's famous girl with a red balloon artwork.

Personally, I prefer Banksy's work, which is thought-provoking and humorous by turns. It is also far less garish than this effort, as Banksy paints in monochrome with just a small splash of colour.