Pseudo-Pincer

four-space pseudo-pincer  

You can't call Black 1 a pincer (see pincer nomenclature) because it doesn't obstruct White's two-space extension to a. Black's reason for playing 1 this way would be to extend from the stone played either to b or c. That is, Black 1 is conceived of as a wedge, rather than a pincer.

Black's strategy might be to slow the game down.

efficiency  

If White now invades the corner, Black can end the sequence with a play at d for a very efficient formation.