The What-If frame is based on the premise of ‘pretending’ to believe something different. The What-If frame, also know as the As-If frame, is used to assist a person to consider more ideas, options and possibilities, that they may not have otherwise considered.
The intention is that by facilitating that person in trying on those different beliefs their rigid model of the world is given a good hard shake (or a gentle shake if that’s more appropriate) and they push past their limiting beliefs in the direction of more useful beliefs.