I have "Safe Search" turned off. Nevertheless, Google seems to return results that are deliberately sanitized.
For example, an image of a middle-aged woman holding her breasts and kneeling before a nude middle-aged man and sucking his cock returns results labeled "Man," with other images of men in underwear with a few couples thrown in. ETA: The images are not explicit.
For example, a holiday snap of girlfriend topless, nothing sexual, returns results labeled "Barechested," with images of bare-chested men.
The results don't vary if I'm signed in to Google or not. Searches based on text strings, e.g., "cocksucking" return the expected list of porn sites.
Has Google changed its image search algorithm? This is important for those of us doing professional research.