I also tried the other way: giving it NSFW images.
I can't show those, but it did pretty abysmally. it spotted a penis in one, but an image of two people having sex that was shot from the side? marked SFW. A softcore shot of BDSM? SFW

I tested to see if it wasn't programmed to detect clitorises (clitorii?), thinking maybe it the thinkpad pointer is a clit and not a nipple?

NOPE! I tried turning the detection threshold way down and it managed to detect 27 overlapping pussies (their term, not mine) but zero clitorises.

So I guess it just can't detect clitorises. shame

man, this thing loves to mark my thumb as a penis.

I tried running it on some VHS tape covers but instead of noticing the woman in a leotard on the cover, it told me it was NSFW because my thumb at the bottom of the image was DEFINITELY a penis

this is anti-thumb prejudice!

I tried a photo where I was wearing nitrile gloves while holding up a phone, and it didn't mark my thumb as a penis this time!

it did mark my blurry wife in the background as a sex toy, which is more offensive tbh

if I lower the confidence threshold enough it'll detect my pupils as nipples

I keep trying laserdisc covers and it keeps telling me NSFW and then points out the thumb in the corner as a penis

kinda want to run it on my entire photo library and see what it marks as NSFW.

yeah I don't know why that specific pluot is a penis

I ran it on a photo of me holding a box of Rice-A-Roni, and it marked my hand TWICE as penises, and the "A" in Rice-A-Roni as an asshole

MY MOUSE WHEEL IS NOT A NIPPLE

HAH. it failed on my USB penis
This is 100% safe, baby!

(it's a plastic USB flashdrive in the shape of a penis)

maybe it should be a game.
like it shows you pictures like this, and asks you if you can guess where the NSFW detector thinks the problem is