nbc cameras were able to get a sneak peek at last night s dress rehearsals inside the olympic stadium in the east end of london. of course, her majesty, the queen, will be at the big event and stephen colbert got a preview of royal protocol last night from the british ambassador to the united states. do you have to report to her? not very often. really? but sometimes? sometimes. is it true that you don t turn your back on her? that is true. you just back out of the room? do you have like mirrors on your palms and go does it go beep, beep, beep, when you re going away from her? it s not quite like that. what you do is you do a little neck bow to take your leave, then you can actually turn and walk out forward so you don t walk into the furniture backwards. there s no bowing here. joining me now, the british