Please see the traditional picture of Dikshitar. His holding Veena and playing is opposite of current style - Resonator on the left.
What is the correct style?
Mudduswami deekshita's portrait is as painted and depicted by the Maestro Shri S.Rajam Sir. Rajam Sir must have researched about the manner of Mudduswami Deekshita and painted. This manner is a very rare instance. The position right for achieving the judicious balance between 'Gottu' and 'Meettu' excellence is the criterion in veena playing.
Srikant is right, the pictures are inverted as a mirror image would be.
TyagarAja and ShyAma shAstri are depicted holding the tambUra in the left-hand, and their sacred threads and shawls are on the wrong shoulder [the prAcInAvIti style worn during performing funereal rites]. Rama too, has interchanged bow and arrow.