How does that settle anything? You're being rather vague.
Even if you want to say it's not a camera(or something?) deliberately posing posing for the viewer in a sexy playful manner is like, the exact opposite of "casual"
"Nudity that is, within the picture's context, not overtly sexual and/or provocative."
I always took it as "not tryin to be sexy" like someone just siting/walking rather than simply relaxed. There are lots of pictures with relaxed attitudes that are clearly sexual, while there are pictures where someone is playing or engaged in other activity in the pool.
She's clearly being provocative here and I'd say pretty overtly sexual.
I think what people are looking for is "artistic nude" here