The difference is when you draw by memory you won't remember every tiny detail, and you make/draw it in your own way vs. having the object in front of you you can copy it almost exactly.
Hearing different viewpoints and the facts that go with that
Giddy Up
Social protest is usually executed by the general population. It is intended to create awareness of an issues or several issues in order to increase support and further change. Political motive is what drives politicians and leaders to instill changes or take positions on subjects in order to further their power.