Compromised diagonal and dropping back
This sort of pattern on the side is quite common after an invasion:
You could call a dropping back idea; it is certainly also a getting ahead idea. In this case Black doesn't cut with Black a, White b, Black c because White d is a tesuji of the flying-off kind.
To play at a is clearly slower and heavier, even though it has more effect on Black too.
Here is a very special case of this shape.
This choice of (instead of Black at a, in the 3-5 point, 4-3 approach, one-space pincer) is an example of a play that is recorded in joseki dictionaries, but rarely seen in pro games.
From what is said at weak player's diagonal, one can understand the rarity: Black at a is very natural from the point of view of shape. Of course can be called a lighter play.
This example game in which was played (Kori Toshio-Kajiwara Takeo (B) 1982-03-04) is a good example of Kajiwara's style. We join it at Black 33.[1]
Presumably is intended as a sort of inducing move. Black wastes no time playing at another key point of White's diagonal.
Kajiwara was nicknamed 'the drill' for his maximum attitude to local play: is a good example. A ko results.
Here (dropping back with a diagonal play) shuts White in, rather than chase him out into the centre.
[1] The opening plays were these: