I believe that it's 2nd BEF back from a week in Normandy via Cherbourg, hence the re-embarked vehicles. There could well be some Lines of Communication stragglers in there too.
Many of those who came back via Operation Aerial had not seen any fighting.
That looks very like an RASC that has been painted over on the tank. A fascinating picture - the rifles all seem to be the Lee Enfield No 3 mk 1, which would have been fine, but certainly not the modern No 4 rifle. I'm sure others (more expert than I am) will find other good details. I'm intrigued by that strange 'T' shape on the tool box....
Looks as if the censor also scribbled on the headlight. I wonder why...
Also noticed the T shape on the toolbox. Thought it was the shadow of the kickstarter... But when I look again, I think I'm wrong. No idea what it could be...