Women are indeed held to different standards. For example, a woman viewing this image at work is unlikely to get in trouble for it. A man's motivations for look

Women are indeed held to different standards. For example, a woman viewing this image at work is unlikely to get in trouble for it. A man's motivations for looking at it are more likely to be questioned and judged, which is why they have to be more careful about any content that could be considered NSFW. The same goes for Michelangelo's David. Because there is a default assumption of heterosexuality (and gay men are not considered a threat by a protected group), David is not going to arouse suspicion, no matter who is viewing it. Female nudes are a different matter, not because nudity in art is judged differently by the subject's gender, but because the viewer is judged differently because of their gender.