"Everything is a Representation" suggests that all reality is just an imitation of an underlying form. For instance, when you draw a circle, you are actually imitating the shape of a circle. Similarly, when you create artwork, you are actually imitating an object from the physical world. The artist then imitates the form of the object, and so the creation is ultimately a representation of beauty.
"Representation matters" is a phrase that recurs in many industries. The phrase has been embraced by those who want to rebel against defaults. But it is also a catchphrase for underrepresented groups. When young children see examples of people similar to them, they are often encouraged to dream big. But it's important to remember that a lack of representation shouldn't rob you of individuality.
Although objects don't have a consistent meaning, people can construct meaning for them. For post-structuralists, representation is larger than any individual representation. And it extends beyond language. For example, we can talk about "art" and "music" as two separate but overlapping things.
Aristotle disagreed with Plato and argued that "forms" create reality. While acorns have a form of an oak tree, they may become an oak tree under the right conditions. By focusing on representation, we can see that our world is made of a number of distinct forms.
Representations make computational tasks easier. In particular, choosing the right representation helps us write efficient algorithms. Different computational tasks require different representations. So, it is important to consider all of the possibilities before designing a representation. It's tempting to select a single data structure and target it for optimal performance.
While Schopenhauer didn't say "everything is a representation", he did suggest that everything is an object of our will. This position is similar to the Upanishads, which form the basis of Hinduism. However, he did not use an Upanishad to reach this position, but he used the account of a European explorer to convey his point.