Perspective projected views are calculated based on the distance from a theoretical camera and target point. The shorter the distance between the camera and the target point, the more distorted the perspective effect appears; greater distances produce less distorted effects on the model.
The following illustration shows the same model viewed from the same viewing direction, but with different view projections (Orthographic versus Perspective).
When the view for a model changes, the view is updated using the last projection mode unless the current projection mode set for the ViewCube is Perspective with Ortho Faces. The Perspective with Ortho Faces mode forces all views to be displayed in perspective projection unless the model is being viewed from one of the face views: top, bottom, front, back, left, or right.