Both the blue tit and great tit were looking in the same direction so I don't know what they were looking at. Sometimes birds fly out of the wisteria growing on the garage so maybe they thought they were about to be joined by another bird.
Thank you for getting yesterday's robin on PP and for all your kind comments and Favs. It is always very much appreciated.
Thanks for letting me know about the TT Rosie, I had no idea!