What is the definition of
abstraction

The act process of leaving out of consideration one or more properties of a complex object so as to attend to others; analysis. Thus, when the mind considers the form of a tree by itself, or the colour of the leaves as separate from their size or figure, the act is called abstraction.

if you look up in the top right corner you'll see your current profile picture, click than click "view profile" you'll be able to change it there.