Very specific project-related scenarios where there is a hang up due to unforeseen circumstances, such as problems with user testing, complications due to pre-existing project relationships and constraints of established platforms. If you are interviewing for a design position, know how to pair what you do effectively with a business need. It's not about choosing colors (because you can't, really, there are already established brand guidelines.) You need to be able to show the value of design-driven solutions and how to reach users on a responsive level.