“Please ensure any outfit worn is appropriate for a school setting and holds cultural significance”

It is quite clear her outfit, which is completely hideous, was not appropriate for a school setting, nor did it have cultural significance. If she’d turned up to a wear anything you want day like this then not a single person would have given a tiny rat’s ass.

Of course you can just ignore that and make ignorant and angry comments that make you sound some kind of incel. That’s what they wanted with the story after all. Angry people are easier to manipulate.

How is the outfit inappropriate for a school setting? That's sounds like something a strict religious school driven by moralism would claim. And how is a flag not culturally significant as a symbol and token of belonging? I suppose you go to various protests and instruct people to tuck away their flags since they lack relevance. This is a very strange take on the situation. Heck; let's not even flag on national holidays in our nations.

Also, calling people "incel" is a not a great way to promote your own stellar views or superiority. Angry people are easy to manipulate, you seem quite angry yourself, based on the language in your post. Introspection is your friend.

Edit; before anyone has a heart-attack - she wore a bowler hat, just about the most iconic English design there is, along with the silhouette of the Aston Martin DB5 and the Big Ben.

If you turn up to school in a sequin covered dress and a hat you are going to get into trouble, yes. Schools have actual dress codes in the UK. 

A flag is obviously not a culturally appropriate attire, being that it isn’t attire at all. Similarly if she’d worn a Scone that also wouldn’t be appropriate, despite scones being quite lovely, and completely inoffensive.

"As a part of the celebration, we would like to invite students to wear traditional cultural dress to school instead of their usual school uniform." From the school information sheet itself, fully covered in the article. I don't think you should comment on other people's outrage of failing reading comprehension if you missed this vital detail.

Also, sequin dress is classic Victorian wear, inherited and adopted from all the way back to ancient times. It was all the rage between 1700-1950 in many circles and nations, England being among them. And the Bowler hat, as mentioned, is quintessentially British. 

Comparing flags to pastry is another very odd choice. I get the feeling you're not really after an honest discussion; just some good 'ole pie flinging.

How is the outfit inappropriate for a school setting? That's sounds like something a strict religious school driven by moralism would claim. And how is a flag not culturally significant as a symbol and token of belonging? I suppose you go to various protests and instruct people to tuck away their flags since they lack relevance. This is a very strange take on the situation. Heck; let's not even flag on national holidays in our nations.

Also, calling people "incel" is a not a great way to promote your own stellar views or superiority. Angry people are easy to manipulate, you seem quite angry yourself, based on the language in your post. Introspection is your friend.

Edit; before anyone has a heart-attack - she wore a bowler hat, just about the most iconic English design there is, along with the silhouette of the Aston Martin DB5 and the Big Ben.

Traditional cultural dress is a very specific things, like a Kilt or lederhosen. Not things people just used to wear in a country. 

Her outfit is not a traditional cultural dress. If you think it is then I can’t help you. Feel free to be outraged and angry at Muslims, as per the majority of the comments here. 

And there we have it; where have I mentioned Muslims? You're just here to talk shit and toss age-old labels around. I challenge your strange takes and you mark me some form of racist or bigot based on other peoples' words. Get off your high horse.

I can perfectly well think the school made a mistake, and still don't be a fascist, nazi, or anything along those lines, do you possess enough cognitive powers to fathom such an incredible thing? 

I work with kids (yes; even Muslim ones) and removing someone from class in front of everyone and isolating them is a shameful to do to a child.