One's designs appear on flags (8,6)

I believe the answer is:

pavement artist

'one's' is the definition.
Both the definition and answer are singular nouns.
Perhaps there's a link between them I don't understand?

I don't understand the remainder of the clue.

(Another definition for pavement artist that I've seen is " Painter".)

I've seen this clue in The Guardian.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.