Iran recognized the Argentine Navy and Air Force as terrorist organizations. Nothing more and nothing less. Apparently, this decision was made in response to Buenos Aires adding the Revolutionary Guards to the list of terrorist organizations.
In some ways it is reminiscent of the old story with the Beatles. When reporters asked John Lennon how he felt about an organization being formed in Detroit to ban The Beatles, he replied: "We're forming an organization to ban Detroit."
At the very least, an exchange of diplomatic slaps between Tehran and Buenos Aires has about the same value and meaning.