We make resonance structures because it is otherwise very difficult to simply show the electron density in structures with partial bonds.

NO is a sigma acceptor but a pi donor. It is an ortho-para director, similar to halogens. https://www.masterorganicchemistry.com/2018/03/05/why-are-halogens-ortho-para-directors/

Thanks for weighing in Paul!

General chemistry teaches the evils of charge separation, but far, far overstates it. Charge separation is awful in the gas-phase, but in polar/complexing solvent, it is not nearly as bad as is suggested. The bigger, overriding issue is not the charge separation but the lack of the octet that normally accompanies it. I’d take charge separation with octets over no-charge separation without octets (take that “expanded octet” nonsense!).

But even with lack of octets, we know that charge separation is not bad when you have polar bonds. The carbonyl is a very polar bond. Hence, we can say that the polarized resonance structure is important.

I see absolutely no case for charge separation being a factor. Opposite charges attract anyway.

uhhhhh……
I actually mentioned your site as great!!!