While the dresses need to be Edwardian in style, hats really haven’t changed too much, Polly says. “The shapes are largely the same, though we have different materials and they are worn differently.
“The colours are more vibrant as they didn’t have the same quality of dyes, and we now get amazing trims from all over the world.
“Hats were worn differently as the hair would be piled up with pins, with the hat perched on top.”
The shop is perfectly familiar with the needs of Ascot-goers, as they hire out a couple of hundred hats during Ascot week from the Beaconsfield shop, and a similar number from their Wendover branch.
When Danielle Owens, who plays Eliza, went along to Shu-Shu in Beaconsfield, the three of them had great fun trying on hats to find the ideal choice for Ascot.
Being a keen singer, dancer and actress Danielle immediately wore her hat with aplomb, while admitting she never wears one in real life, managing a pub at Berkhamsted with her father.
But most people, Polly says, are timid about choosing a hat for a special occasion.
 “They almost all say, ‘I’m not a hat person.’ But we assure them that there’s a hat to suit every face, outfit and occasion.
 “It also needs to fit well and be worn properly.”
She encourages women to bring their outfit when choosing a hat, to make sure the hat balances the outfit. The extra wide brim of Eliza’s fuschia hat, she points out, works because her dress is long, but would not work with a slim, short dress.