I would also say that the audience is more wide-reaching across London compared to N.Y.C. Going to a show here is a more casual experience, and most people who attend are not hard-core theatre fans and incorporate a performance as part of their average evening plan. Perhaps as a result, stage-dooring is not as frantic or as crowded on the West End as it often is on Broadway. Those waiting after the show stand politely as actors come out, although their presence is not a guarentee that an actor will stop at all. I experienced this first-hand when my friend and I were stage-dooring for Phantom of the Opera: principle cast members walked straight by without a second glance, and when they did stop, the expectation was that the fans brought their own pen for signatures. In fact, the only person who had her own Sharpie at the ready was the sole American actress in the production.
The other biggest difference between Broadway and the West End is that programs are not provided with your ticket. Rather, it is a separate, optional purchase once you arrive at the theatre. Having bought a program for Phantom to commemorate my first West End show, I will say that the extra cost makes sense after seeing how high quality the programs are. They are typically printed larger in size compared to a Broadway playbill, and provide much more information/photos with little advertising beyond inserts for other shows. One thing that does stay consistent across the pond though is, of course, the audience members' enjoyment of taking a picture of the set, regardless of whether a program is held in front of it or not.
