3-4 point, high approach, ogeima
According to All About Joseki, the downside to instead of the usual play at is that now an invasion by white at y is less severe because a black play at z is sente, which would not be the case with at .
Professional play tells that if black plays tenuki, white's aim is to attack at b.
Cutting through the ogeima is not seen in pro play. The cross-cut - is inevitable. Then White has many options.
The atari doesn't look too good. Black gets a big corner and White's shape is troubled by a.
The descent is not as sharp. Black is easier here than in the "simplest" diagram.