I'm thinking that Margaret was so excited about this wedding, she wanted to be sure to bring along a pom-pon in case she felt like doing an impromptu cheerleading routine in Poet's Corner.  Otherwise, I have no explanation for this, other than: 1986.

But maybe we should all just be glad it's not human hair this time?

Princess Margaret and her mum appear to have coordinated their outfits for Anne's wedding.  Here's a look at the neutral colors and brown fur from a color photograph:

Shiny, patterned fabric and brown fur -- 1970s all around!

ETA: A closer image, courtesy Jake.  No, Margaret, too shiny!  Egads!

Okay, hatters, are you sitting down?  Are you?  Good -- because I wouldn't want you to see this until you were properly prepared:

I mean, from the front, Princess Margaret's chapeau for her cousin's wedding doesn't seem that out of the ordinary for a big '60s society event.

But then...

Yep, that's exactly what you think it is.  And, fair enough -- when I find my headwear's a little boring, I think, "You know what would make this a little jazzier?  A Donald Trump-style combover!"

Princess Margaret was such a stunning royal bride -- maybe one of the most beautiful of the 20th century.  Her dress and her veil were both very much of the era, but her tiara was a nineteenth-century stunner.

This is, of course, the famous Poltimore Tiara.  It's an antique piece, made by Garrards in 1870, but it's not an heirloom Windsor tiara; instead, it was bought for Margaret.  The tiara was originally made for Florence, Lady Poltimore, the wife of the 2nd Baron Poltimore.  Lady Stucley, the daughter of the 4th Baron Poltimore, was the member of the family who sold the tiara.

It's sort of surprising, because this tiara is just so massive, but it actually can be converted and worn in other configurations -- as a massive diamond necklace, as well as a set of brooches.  Alas, no British royal brides will be donning the Poltimore any time soon; it was sold in 2006 as a part of an auction of Margaret's jewelry after her death, apparently purchased by a Chinese collector.

How lovely was Princess Margaret in her bridesmaid outfit at her big sister's wedding?  I love the whole thing, but the wreaths worn by the bridesmaids are one of my favorite parts of the outfit:

Gorgeous!  I love the way they echo ears of wheat -- a traditional symbol of good luck and fertility in marriage.

Also -- recognize the little boy standing in front of Margaret?  That'd be Prince Michael of Kent!