Graphic design does not work just on a flat plane. All graphics are experienced in a physical context. Allowances must be made for the three-dimensional world, like allowing for appropriate margin in printed books, and screen resolution in ebooks.
Consider the design of the brightness icon on the brightness control knob. There is not a lot of room for a complex visual. There is also a safety implication with overloading the user with unnecessary information.
The brightness knob is already physically attached to the instrument it affects. There is no need for the icon to show a representation of the instrument.
Using the standard sun brightness icon should be enough. Tis results in a Less cluttered and immediately more legible design.
Too many graphic design work still happens in isolation without acknowledging the physical context the work will be experienced in.
When you next engage a graphic designer, ask for mockups of the proposed designs deployed in likely physical contexts.
