Quite some time has passed since I last posted on this topic. Since then I've seen a few reminders of What NOT to Wear to a Milonga so I'll just post them for your viewing edification.
On a young and skinny performing dancer, this very short skirt, fishnets, and lots of "tango" accessories might work. But on this lady, it definitely didn't, since she had none of those qualities.
The lady in white certainly had her own style, sort of a Snow Queen vibe going on. The outfit might have been alright if the dress hadn't been transparent, if she'd lost the hat, and worn white shoes to match the tights. And if her posture were better, she might get away with the whole look.
This fishnet photo below just serves as a warning: if your legs are less than gorgeous, don't call attention to them. But the secret to fishnets is--wear nude tights underneath.