Next Saturday is the real thing. The Trooping of the colours is an annual event held on the official birthday of the monarch. Unlike the rest of us she gets two birthdays. Her real one is 26 April, then the official one when she checks out her troops in this spectacular parade.
These big events have to be perfect. So there are a couple of trial runs. Yesterday was rehearsal number two. If you don't mind the carriages being empty, then these days are a great way to get a good view of proceedings. In fact you can apply to get a ringside ticket. It is done by ballot each year.