Whatever the intention and inspiration, the result is absolutely beautiful.
Still, they are dating and are a happy couple.
Based on her hair and what we can see of her dress, Anna looks like she's ready for prom or something like that, but when all is said and done, she looks so good we could care less about context, after all, it's just a shoot, and they generally make no sense.
So sit back tight and enjoy! So, you know, if you ever see her at the bar, be sure to mention this and have a convincing way of lying about your involvement, it may be a good angle to take.