This is taken from a three stone handicap game. I am not sure if the Black player does not know how to play the joseki.
The development of the upper left corner halted temporarily with , and both players played elsewhere after that.
However, we can see that Black's position is full of bad aji. This includes White starting a fight by pulling out at a, also, the cutting points at b and c are also aji.
For the purposes of aji discussion, it is rather obvious that leaves behind serious bad aji. It should have been played at c or instead.
A possible future development might be for White to cut at , although this never happened in the game.
Immediately the aji gets further exposed: White can cause further damage by playing at and . Black will lose a group of three stones due to connect and die or snapback.