Why is the go to mother of bride outfit a hideous stiff coat dress with hat?

This sort of style does really vary between countries. We went to a wedding in Switzerland, the bride's family were from Eastern Europe and all the women wore very sequined, very "blingy" dresses which you wouldn't see at a British wedding. I was at another wedding where the groom was Swedish and a lot of the men were in jeans and casual shirts - again you wouldn't see that here.

I googled "mother of the bride outfits in Spanish" and a lot of it was floor length gowns which may be the thing there, but would look out of place here. I am not a fan of the coat/dress look though to be fair.

They’re all ugly and dated though.

It really wouldn’t. I’m a tall size 20 and I’d look like a tent in that.

I call it the Tory Lady Mayoress look 🤣
When I was M of B, I had lovely inspiration from Pinterest. Best wishes for your day.

Agreed.

and never in a million years would the second dress suit a larger person. That style is made for long svelte ladies

You yesterday evening: "Not one of my European aunts would ever wear that style. It is not the wedding costume for mature women in my home country."

And: "This is absolutely not the go to in my home country."

Maybe people are 'trying to other you' as non-British because you keep stating that your 'home country' is not Britain?

Niece got married earlier this month. Mother of bride wore a dress, jacket/blazer, handbag she had made herself. Blue floral dress, pale blue jacket. Mother of groom wore dark blue dress and pale pink jacket/blazer. One of the other aunties had a kind of stiff lace floral dress with faux fur stole. Slight hint of bride up staging as bride made her dress which was 50s style simple classy. I wore teal velvet blazer over matching top with navy trousers.

When ds1 was getting married DH and I went to John Lewis and had a personal stylist appointment. I had several outfits to choose from and ended up with something similar to your second image, which wasn't expensive. Perhaps your mum could try that? I wasn't keen on the wedding shop outfits and am about 30 years too young to wear them in my opinion!

I go to approximately 200 weddings a year (work-related) and I would say less than 5% of the mothers of the bride wear anything like the formal, structured dress-plus-hat combination these days.

Very, very few people wear hats. A small number have fascinators. Most just have their hair natural and wear a lovely, flowing summer dress or trouser suit which suits them.

I think OP's issue may be due to having gone into a shop and asked for a "mother of the bride" outfit. It sounds to me like that's been interpreted as wanting something different from the rest of the guests. Something a bit more formal, so it's obvious you're part of the wedding party, in the same way that the groomsmen will all be in formal suits.

Perhaps if you ask simply for a "wedding guest" outfit, you'll be shown things which are more your mum's style.

Maybe where you come from but not in the UK it doesn't.
Statement heels lol. Thank goodness my DD doesn't expect me to wear such monstrosities.

I bought my first MoB outfit from Jacques Vert (a sleeveless, blush coloured empire line midi dress) and the second came from Phase Eight (black, long sleeved, knee length). I was only in my 50s both times and wasn't prepared to dress like my mother!

My lovely sister was Mother of the Bride on Friday and she wore a lovely elegant, flowing dress with contrasting fascinator. Nothing stiff and frumpy going on there

It's quite a depressing thought really !

I’m getting more at style of dress. The second would suit a larger lady

It wouldn't. It would have zero elegance. I'm a larger lady.

Some people find breaking from tradition difficult, in case they’re criticised; it’s a safe option.

I prefer to do it my own way, as did my mum. You don’t need a stylist to pick an outfit!

i wore a dress from Scarlett & Jo, as recommended by mumsnet
was wonderful

Wtf are ”statement heels”? Presumably they’re the heels that barely anyone can walk in and which are now virtually obsolete because they look so dated?

Then you post that picture along with A gracefully placed, well made shawl is never dated. I think it’s the perfect thing to wear in the evening for a summer wedding.
I’m in my 50’s and think that looks very dated!

I love those, except for the silver chiffon number.

They are perfect for a very formal daytime occasion. Buckingham palace, wedding, possibly graduation if you can be bothered.

It really is formal wear, to stand among men in morning suits.

I'm really not a fan of the Carole Middleton-style MOB outfit either, but what on earth is that pink and orange monstrosity in the first post? It looks hideously cheap and nasty to me, especially paired with those awful white heels. God almighty. You couldn't pay me to wear that thing. The second dress the OP posted looks like something I'd pay a tenner for to wear on the beach on holiday and never look at again. And 'killer heels'? Awesome, great, let's encourage women to wear items of torture on their feet at their DC's wedding. 🙄

Are they? Odd that they’re the kind of thing the royal family wear on formal occasions if that’s the case.