I've had a couple of complaints, while there's quite a few others that say they had no issue. The scenes are supposed to be quite dark, but the backlight on the models and a faint fill light are there to ensure you'd have no problems making out the silhouette quite clearly, and see a little of the details such as the clothing and a hint of the body shape, but obviously not as well defined as when fully lit up.
It should only apply to either the nighttime living area and sleeping area conversation scenes. All the payoff scenes (couch cuddles, bed cuddles, the hj scene) are well lit up (almost up to the point of breaking immersion), and if you have trouble seeing those, it's definitely time for new hardware or a trip to the optometrist.
So I'm not entirely sure if, for those that did remark on it, if it's art direction gone wrong (having images that are silhouetted being perceived as rendered too dark, instead of intentionally dark), form factor or hardware (smaller screens, unable to adjust gamma/contrast etc), or just bad lighting conditions/glare on the display when people are playing it. But I'm working on figuring it out.