Transform
Shift
Controls the shape of Strength relative to the Steps. A higher Shift nudges generation to focus on the details of the source, a lower one nudges generation to focus on general structure.
The Steps aren't all doing the same job. Bias them early and you influence the overall shape of the result; bias them late and you're refining detail on a shape that's already settled.
Why it matters
A lever that influences the behavior of Steps and Strength — useful when the broad idea is right but the texture isn't, or the reverse.