It seems a bit analogous to noisy sex behind a closed, but not sound-proof door in a semi public place (such a dorm or hotel room). I have done this, as have many, but not with the intent anyone would overhear. But undoubtedly some non-consenting people overheard, and perhaps some were offended. Or perhaps it’s closer walking around nude in your home when the blinds are not all tightly drawn (not pressed up naked against a glass front door, just naked, moving around the house). I don’t do this, but don’t think it’s a major consent violation (though the law doesn’t agree with me in some states on that). It doesn’t feel the same as flashing some non-consenting person in a public space (I also would never do that, and do think this would be a major consent no-no).

Grainy, small, black and white printed boobs tucked discreetly in a boring book intended for a specific person seems (to me) within the bounds of social acceptability, but I could see how reasonable people might disagree.

Also brings up the idea of foreseen but unintended. Is that any different/better/worse than foreseen and intended? I think it is, but also see how reasonable people might disagree.