The artist is using the appeal of pathos (emotional response). They play on the viewers association of the sky with endlessness, as it is often described as such. Additionally, most people associate the sky with birds which are used as mascots which hold value for freedom, like America's bald eagle. Lastly, people have an involuntary reaction to positive stimulus by smiling.
Musicians use a time signature to specify the number of beats in a measure (also called a bar).
The answer to this question is entasis.
Entasis is a design principle in architecture where in a convex curve was applied to a surface which also serves a strength to the construction and it also gives an optical illusion to it. Egyptian pyramids use this design principle.
What color?
The black and white/ blue and white?
If so that the barcode scanner.
Hope this helps any! :)
