Short inventory? Move the whole quote up, so sellers find you attractive and buyers do not.
Distinct from widening. Skewing shifts the midpoint to manage inventory. Widening increases the spread to charge more for uncertainty. They solve different problems and are often used together.
The interview test. An interviewer trades against you repeatedly on one side and watches whether you skew, and whether you skew in the right direction. Getting the direction backwards under pressure is common and fatal.