I recently came across these two beautiful sketches by Milt Kahl. They show Jim Dear and Darling from the film Lady and the Tramp, engaged in some sort of conversation. Milt didn't end up animating these characters, that assignment went to Ken O'Brien.
There is little doubt in my mind that photographs were used as reference in creating these images.
It is always fascinating to me how Milt interprets straight realism and comes up with forms and shapes that can be animated.
Wonderful insight into an early stage of Lady and the Tramp character design.
Ken O'Brien came very close in his animation to what Milt did graphically in the design phase: