He referred her to a pornography website and then gave her his phone number and talked about meeting her, the Herald Sun reported.
An analysis of his laptop by the police revealed that Sandhu had sent another lewd picture to a chat-room user, who had identified herself as a 15-year-old girl from Kensington.
According to the report, the County Court heard that the girl, who has not been located, told him she would have preferred to have seen his face and she was going to report that he was a paedo(phile).
Defence barrister David Gibson said his client, who came to Australia in 2009 on a student visa, had been drinking heavily after a relationship breakdown and the death of his grandmother at the time of the offences.
Sandhu pleaded guilty to using a carriage service both to groom and transmit indecent communication to a person below 16 years of age. The maximum penalties for the offences are 12 years and seven years' imprisonment, respectively.