It's a reference to the Roman:
Quintus Caecilius Pomponianus (born Titus Pomponius; c. November 110 – 31 March 32 BC),1 better known by his cognomen Atticus, was a celebrated editor, banker, and patron of letters from an old but not strictly noble Roman family of the equestrian class and the gens Pomponia. He is best remembered as the closest friend of orator and philosopher Marcus Tullius Cicero as well as other leading contemporaries of upper class Roman society. Cicero's treatise on friendship, De Amicitia was dedicated to him. Their correspondence, often written in subtle code to disguise their political observations, is preserved in Epistulae ad Atticum compiled by Cicero's freedman and personal secretary, Marcus Tullius Tiro. Atticus was known for his elegant taste, sound judgment and financial acumen.
JJ is saying Parker is a sycophant for Spider-Man. A fan boy. A brown-noser. As Atticus was to Cicero.