Only a Nerdy Psychology Student Would Notice this...

...but this shot from Pain & Gain is exactly like the "iceberg diagram" we're show in class: Marky Mark's head above the water, the normal size one, is the reality of things - the level headed side of the character - while the distorted view from under the water is his repressed thoughts. The mind is made of the id, ego and superego; and the id (which deals with desires and urges) is clearly going out of control in this shot (what sets the events of the film in motion, really).

Plus, intentional or not, this shot sort of goes with the old "keeping your head above water" saying. Probably the best few seconds of Michael Bay's career.