Windows : Where does the professional sheen of a GUI application realistically come from?

Windows : Where does the professional sheen of a GUI application realistically come from?
To Access My Live Chat Page,
On Google, Search for "hows tech developer connect"

As promised, I have a secret feature that I want to reveal to you.
This is a YouTube's feature which works on Desktop.
First, Make sure the video is currently in playing mode.
Then, type the letters 'awesome' on your keyboard as the next step.
Your YouTube progress bar will transform into a flashing rainbow.

A short overview of who I am,
Good day, I am Delphi.
I am here to provide you with assistance in answering your questions.
Windows : Where does the professional sheen of a GUI application realistically come from?
If you need more specific information, let me know by leaving a comment or starting a chat.
Don't hesitate to share your answer or insights on the answer by leaving a comment below.
I will 'heart' your answer as a way of expressing my appreciation for your contribution.
from? come the does a realistically Where Windows sheen GUI of professional : application