These images should print with exactly the same dimensions,
else the printer isn't making the same dpi on each axis !
634x576 pixels; HTML size defined as W: 201, H: 180
576x634 pixels; HTML size defined as W: 180, H: 201
634/570 is approx 1.1111 = 201/180
I have no idea how the web browser knows what size to print the image
If the whole process tells the printer that it should be 300 dpi, then the image should measure 2.113 x 1.900 inches.
My laser printer yields 2.115 x 1.890 inches -- pretty dern close.
Carole's little color printer also comes close.