The "sunrise" comment has NOTHING to do with how painters represent the sun. Instead, it concerns the chair in which George Washington sat, as he presided over the Constitutional Convention. It is a high-backed chair with a half-sun on the horizon carved in the top cross piece.
I know that not just because I have seen that chair, but also because of this experience: When I worked for the Commission on the Bicentennial of the Constitution, I attended two local conventions on behalf of the Commission. I was loaned a copy of that chair, which itself was one hundred years old, having been made for the Centennial. I allowed people to sit in that chair, and took their photographs for them.
The quote is likewise inaccurate. Here is exactly what Franklin said to Washington, as the delegates were signing the final document on 17 September, 1787: "I have long wondered, sir, whether the sun on the back of your chair is a rising sun or a setting sun. I know now, sir, that it is a rising sun."
Shapiro could easily have checked this quote and its circumstances on the Internet. I really dislike inaccuracy about the writing and ratification of the Constitution.
Congressman Billybob
Many thanks for your corrections.