The Dubliner will have to explain the photograph - which emerged last week in a newspaper of him singing in a bar in the Falls Road, Belfast - to the Parkhead club at some point on Tuesday.
The former Sunderland and Hibernian player was warned by Celtic in December, 2012 when he attended a memorial event for murdered Real IRA member Alan Ryan.
Celtic, along with the Police and the Scottish FA, are currently investigating Stokes' fellow striker Leigh Griffiths, for allegedly joining Hibs fans, of which he is one, in singing a song calling former Hearts player Rudi Skacel "a refugee" in a pub before the Edinburgh derby at Tynecastle in March.
Ahead of the trip to McDiarmid Park to face St Johnstone on Wednesday night, the Hoops boss backed both players.
He said: "I have not spoken to Anthony, he is going to speak with the club today about it and I will be guided by what they think is best.
"It is not a major deal for me.
"Sometimes I think these stories are blown way out of proportion.
"They are not bad boys and people try to make them out to be something that they are not.
"They are a bit loose sometimes but I like that in their personalities, as long as we can channel it in the right directions.
"I will wait and see what the police investigation brings and we will deal with it accordingly, regarding Leigh.
"I don't think Anthony has done a lot either.
"There is a code of conduct that they have to adhere to and that will come with experience and maturity.
"They are both playing very well but I am not using that as an excuse not to punish them, obviously if I feel the need to punish them then I will."
The champions are closing in on 100 points and 100 goals as they prepare to take on the William Hill Scottish Cup finalists.
With two games remaining Celtic, who have only lost once in the league this season, to Aberdeen at Pittodrie, have amassed 95 points and have scored 96 goals.
The former Celtic skipper said: "Getting 100 goals would be fantastic and getting 100 points would be a mark of fantastic consistency.
"It seems such a long time ago since we won the league but the football we are playing is very good.
"The intensity and attitude is fantastic so we are in a very good place at the minute."
Left-back Emilio Izaguirre will play no further part for the champions this season after being allowed time off before meeting up with Honduras ahead of the World Cup.
"He's away," said Lennon. "We've given him some time off before he meets up with Honduras."