If you want a portrait likeness, don’t paint exactly what you
see. John Singer Sargent certainly didn’t copy appearances, as
this photo/painting comparison attests. He exaggerated the
character of his subject, Coventry Patmore. Sargent made the
neck longer, the hair fuller, the face bonier, and the mustache
more “twirly.” To be clear, the painting was done from life, not
from the photo, but both date from the mid 1890s. Patmore was so
impressed with Sargent’s interpretation of him that he wrote:
“He seems to me to be the greatest, not only of living English
portrait painters, but of all English portrait painters; and to
be thus invited to sit to him for my picture is among the most
signal honours I have ever received.” From the book John Singer
Sargent by Richard Ormond, 1970, figure 21 and 22. Thanks,
Barry! ADDENDUM: Don't miss the fascinating string of comments
on the subject of sight-size practice.