Alignment has to do with how the body holds the stick.
Aim is how the stick impacts CB and follows through.
Either being off can ruin the shot.
How to tell.
Keep you head absolutely still before, during, and after the stroke until CB impacts OB.
Still enough to see the deflection of CB and swerve of CB as it rolls down table
Still enough to see the CB OB impact and the directions of both CB and OB afterwards