Wikipedia has a good description of the party at "Trooping The Colour".

Winnie9212 posted this highlights video on YouTube. The 1st Battalion, Grenadier Guards just got home from a combat tour in Afghanistan. The Queen presented them with a new Flag last month which had that campaign inscribed on it. They were chosen as participants in this year's parade, and their new flag was the Colour that was Trooped.

If you look at the above video and think the Grenadier Guards are a bunch of spit-shined candy asses in red coats and bear skin hats, consider that the regiment is 350 years old and has fought all over the world. Wikipedia has an article about the Grenadier Guards.

For a more detailed look at the Grenadier Guards and Trooping The Colour, take a look at this video that was posted on YouTube by DigbyCaballero it's fascinating, but it's marked 1 of 11, so unless you're really interested in the subject, this first video may be enough info for you. If you want to view all 11 videos, they're about 10 minutes each, all under the name DigbyCaballero and all titled: Trooping The Colour, The Queen's Birthday Parade 2010.
 

My ancestors were Irish, Scottish and some Englishmen who left England for Massachusetts in 1630. So, probably none of my ancestors liked the English very much. But I've got to admire a little country that brought civilization to much of the world, whatever their motives. Last century, they held off Kaiser Bill and Adolph long enough for America to come over and help out. English literature is the best justification I have ever seen for cutting down trees to make paper. The world would be much less pleasant today if there had never been an England.

Now, as to my headline comparison:

You will notice that Her Majesty and his excrement are standing in approximately identical postures as the National Anthems of their respective countries are played. "What's the problem?" you ask.

Well, in Great Britain, the National Anthem honors the Reigning Monarch, Queen Elizabeth II. So it is proper for her to stand quietly as she receives the salute of those present.

In the United States, the National Anthem honors the Flag of the Nation. It is proper for all to face the Flag or face the source of the music, and salute, if military, or place the right hand over the heart, if civilian.*

*It should be noted that in international diplomacy, "the Kenyan crotch salute" is regarded as a vile insult in most countries and has been the primary cause of several conflicts resulting in thousands of deaths. This is the reason most countries do not have Kenyan embassies.