Siva in dakshinamoorti form wearing 2 different type of kundalams - especially patra kundalam in left year at Veeratteswarar temple Tiruttani - Aparajitha Pallava period.
Simillarly All Rajagopala images have different kundalams on both ears - Patra Kundalam in the left ear. You can see it in many temples - manimangalam, ponneri etc . the enclosd image is of RRC/Rjc period. ( won't tell the place)
We saw in Manimangalam post that Raja Gopala is Devi swaroopam - is he is Sri Viday's male form.
Kalidasa in Shyamala dandagam mentions that the godess
Vallaki vadana prakriya lola thali dhala badha thadanga bhoosha viseshanwithe, Sidha sammanithe, Who wears the ear ornaments made of palm leaves when she plays the musical instrument called Vallaki*, Who is recognized by great sages,
What i think is ( only assumption) - since the left part of Siva belongs to Devi - that is why he is shown with Patra Kundalam. Rajagopala is also shown to denote that he is Srividya himself.