I wouldn’t class ANY of those dresses as “barely there”. I was expected much worse. Other than the length in most, I don’t really see the issue with the dresses. It’s Cannes, nothing new for them and the weather is usually quite warm since it’s the South of France. Most of those dresses would trap heat if it wasn’t for the slits in them.
I will point out if we’re going to go with the age route (which is ridiculous IMO), several of the women photographed are fashion models so likely not older than 30.
Side note: I’m in love with Stella’s nude dress. Absolutely gorgeous.