The images were relaxed and playful, posted by players who had already done their day's work by swatting away Aberdeen. If they had stumbled at Pittodrie those pictures would never have seen the light of day.
Champions League fixtures are always a distraction for Celtic - they lost or drew nine times immediately before or after European games last season - and their focus could have been clouded on Saturday by the knowledge that they were going to Aberdeen Airport after the match. Three-and-a-half hours after full-time they set off for Kazakhstan and a fixture far more important than any single league game they will face this season or next. By take-off time, what might have been a trying afternoon had instead delivered a victory, no injuries, and some welcome game time for substitute Virgil van Dijk. They couldn't have asked for more.
The contrast between Celtic's performances domestically and in Europe is often so profound that manager Neil Lennon need not be concerned about the lack of vibrancy or danger in their play at Pittodrie. Celtic's passing was neat and composed, and often of high quality, but they had Georgios Samaras wide left and Commons and Scott Brown supporting in a system without an attacking figurehead. Aberdeen were dealing with them comfortably until Jamie Langfield was sent off for clawing away Samaras' feet. The former had to go, just as Fifa has to address the disproportionate punishment of a penalty and a straight red card when it is a goalkeeper who denies a goalscoring opportunity.
Commons converted the spot-kick and that was that, game over on the stroke of half-time. Aberdeen performed with purpose and shape throughout and Niall McGinn, of all people, planted a header in Fraser Forster's hands from point-blank range when he should have made it 1-1. But Celtic played within themselves and predictably scored a late second when James Forrest's speculative shot looped off Mark Reynolds and over substitute goalkeeper Nicky Weaver.
"The manager drilled it into us that we had to focus on Pittodrie and I felt we did that," said Charlie Mulgrew, the Celtic player. "We knew it would be hard as Aberdeen have started the season well and that always brings the crowd to the stadium. They've got a great support as a massive club. I actually think it's good to see, it can only be good for the league."
Naturally Mulgrew himself was consistently jeered for defecting to Celtic from Pittodrie. "I know the supporters still boo me but I can't do anything about that. I had some good times at the club and if they choose to boo that's up to them."
His Aberdeen past will work to Mulgrew's advantage in one respect. He has spoken to his former team-mate, Stuart Duff, who now plays in Kazakhstan and has been an informant on Shakhter Karagandy, the Champions League play-off round first-leg opponents awaiting Celtic on an artificial surface in Astana. "He said they're a big side who like to get it forward early," said Mulgrew. "They also have a long throw in. That's just about all I know. We'll just need to deal with it and if it's a battle then we'll need to match them. It's usually different when we play in Europe, [with] teams that like to keep the ball, but we'll deal with whatever comes our way. They're going to be a good side because they have got this far by beating decent teams along the way. They're not going to be anyone's mugs so the last thing we're going to do is approach it with a bad attitude."
As for Aberdeen, they look as likely to finish second now as they did before losing under Derek McInnes for the first time in his eight competitive games in charge. The result was very familiar but Langfield's red card weakened them to the extent proper judgement had to be suspended.
In Michael Hector they have an impressive young centre-half who could replace Russell Anderson, while the real test for McInnes is how many points they put on the board before next confronting Celtic, at Parkhead late in November. The team that finishes second this season is one that goes to somewhere like Tynecastle and wins. Aberdeen are there on Saturday.
Losing yet again to Celtic deflated the 16,000 home supporters but the red card shown to Langfield softened the disappointment and they left Pittodrie ready to regroup for the rest of the season. The worst possible outcome - a weak capitulation and a heavy defeat - would have burst the bubble and thousands would have disappeared again. "It's really important the crowd stay with us," said Joe Shaughnessy, the Aberdeen right-back. "As a player it's great to walk out the tunnel and see the seats are full. How we respond to this is important."