I too bristled against the "We are all designers" language at first. However, I reluctantly accepted that it's true. Many of my colleagues are doing design work, though not always the best.
What's more accurate to say is that we are not all skilled designers. (I intentionally don't say professional - technically a professional is just defined as belonging to a profession, which again, you can be unskilled at.)
You can't say that the artist who did the restoration is not an artist. Cecilia is just an unskilled restorationist.