jomo the opposite actually:
Set angle to No: the angle of motion will be independent to the display angle (self.angle) of the object (think of a ghost in a pacman, it does not rotate visually when the angle of motion changes, always the top of the head at the top, and the bottom at the bottom)
set angle to yes: the angle of motion will set the actual display angle (self.angle) to the angle of motion of the object (think of a pacman, it rotates with the direction it goes to to have his mouth going forward), the angle of motion is the one to overwrite the display angle.
Aphrodite Thanks for your comments. And what you've described is the same with my original understanding - before I made the capx which attached with this post. I have no idea how to explain what I see.
And if you rotate the [Sprite2]'s angle to 0 in <Layout 1>, you'll see some more interesting things.
After that, set [Sprite2]' angle to 0.5, you might start to feel what i'm feeling now.