The difference between France and a liberal nation

We would not say, ourselves, that we are greatly in favour of the burkini and other such manifestations of Islamic prurience. Yet we would, as with people saying things we might not agree with, insist that the populace should be allowed to dress themselves in any such manner that doesn't actually frighten the animals. This is rather the point of a liberal polity in fact: although that seems not to be a view shared by parts of the French state:

Learning of the quintessentially British brand’s decision to release the burkini, Laurence Rossignol, France’s women’s rights minister, slammed the move as kowtowing to misogynists and religious conservatives, adding that women in favour were like "negroes who supported slavery".
Speaking to RMC radio, Ms Rossignol said: “What’s at stake is social control over women’s bodies. When brands invest in this Islamic garment market, they are shirking their responsibilities and are promoting women’s bodies being locked up.”
“You cannot pass off as trivial and harmless the fact that big brands are investing in a market that puts Muslim women in a situation of having to wear that.”

We can and would pass off as entirely trivial that such garments are being produced, even for the purpose of making money. For it is not, except with that animals exception, for the State to detail how the population may dress. Nor even for said authorities to determine how modest women may or must be.

A liberal society lets people decide for themselves. Sure, people might get some very odd looks, a bit of social pushback, wearing a burkini, same as a thong and some dental floss at the beach might garner excessive attention. But it is for those who dress this way and those around them to sort out, not for those who collect the tax and control the men with guns.

After all, it is entirely legal for a woman to uncover her breasts on a French beach but no one has ever said that it's mandatory. So too with unveiling or covering up any other part of the body.

The clothing ode of the populace is for said populace to determine and no, not through the tyranny of the majority either. In, that is, a liberal polity.