I don't think the photo is a fake, but I also don't think it was taken in Luz. My reasons are that the balls are adult balls which children wouldn't have been using, and I don't think a tennis coach would allow sandals to be worn. I'm also surprised at the speed with which the photo was shared with friends.
So what?
We were told it was taken in Luz.
With respect G - they were on holiday - not training for Wimbledon. I doubt if such meticulous rules would have been applied to children simply having fun. It would seem that it was Cat and not a tennis coach who supervised the children's tennis session.
Quote from Kate's book
During Gerry's tennis lesson, Madeleine and Ella came to the adjoining court with their Mini Club for a mini-tennis session. Jane and I stayed to watch them. It chokes me remembering how my heart soared with pride in Madeleine that morning. She was so happy and obviously enjoying herself.
Standing there listening intently to Cat's instructions.........snipEnd quote
I'm struggling to understand what 'cunning plan' could possibly have been devised which required Kate to make up an untrue account of what happened. What would the purpose of that 'plan' be? It makes no sense to me.
I see nothing odd in a very recent photograph of Madeleine being sent to one of their friends who had offered to help back in the UK . They were frantic to get the news of her disappearance out into the public domain at the time - but had been told by the PJ that there could be no publicity in Portugal. It was left to them to appeal to the the public for help via their friends. They chose to send the tennis ball piccie. For the life of me I can't see anything sinister in any of that.
AIMHO