Throughout the X-Men film franchise, Mystique has a form that she uses as a "default" human appearance, as portrayed by Rebecca Romijn and later (earlier?) Jennifer Lawrence.
Is this form "natural" to her? If she was a non-mutant, would she appear this way? If she just wanted to form a human appearance without thinking about it, would it be this form?
Or is this form entirely constructed? Is this the form she consciously designs and creates because she likes it the most?
This question pertains to the film continuity only.