When watching various streams, YouTube videos or LCS, I notice almost ALL the junglers doing this.
They attack, then turn away for a very very brief moment, the auto attack, then repeat this process until the jungle monster dies.
However, they are not soft resetting the camp, as they are not walking out to the boundary for the camp reset. They are still within melee range, but just turn away briefly then resume attacking.
This would make sense if they had somewhere to go to immediately afterwards and wished to in some sense 'kite' the jungle monster so they can get to the desired location faster. However, in terms of net position, they are pretty much not moving at all.
It appears that they take the same amount of damage, they don't seem to be auto attacking any faster so it can't be because of some sort of animation cancelling, so at this stage I see no advantages to doing this. One could argue that it's to make skillshots harder to land if there was an enemy out of their field of vision, but the movements are so minute that it doesn't seem like it will make any difference.
Why do they do this instead of just standing there and auto attacking?
I am happy to be corrected regarding my observations above. Perhaps they do take less damage, perhaps it does make a difference in terms of making skillshots harder to land etc.