You will learn to create a double-take reaction. You will understand the timing issues with a double-take and successfully animate the delayed second take the character acts out.
Why Is This Important?
This is a subtle reaction shot with a quick second look. The double take helps the audience understand the character was not paying attention the first time it looked to the side. The delayed second look creates the illusion the character was looking but not seeing whatever is over there. When a second, faster, take happens the after effect is one of spilt-second reconsidering on the part of the character. This has the effect of making it seem like the character actually re-thinks a previous thought! Very subtle and effective.