4. The hind legs of a keyboard are to help the user see the keyboard in a better angle.
5. The dress pants or trousers creasing is as old as the 19th Back in the day, European factories used to fold the clothes so hard during the shipping process that when the clothes finally reached to their destinations, clothes would have a lot of creases on it. It came to a point that it became a part of the usual attire.
6. The diamond-shaped, pig nose symbol on a lot of backpacks is for hikers and climbers to attach a rope or a metal loop. Athletes can also tie their shoes without using their hands.