Mmmm...nope, just not horrified. On a par with chewing gum or a disposable nappy - a bit grubby, but so long as it's in the bin, so what?
At my place of work it's blatantly obvious that someone, several months ago, removed a sodden tampon - as there's a line of splatters up the emulsioned wall exactly where you'd expect them to be if a squatting person tugged to remove an overfull tampon & then swung it out from between their legs!
Had that been me, I'd've gone & found a damp paper towel & wiped my blood off the wall. Possibly one of my colleagues was mortified at the mess they'd made & just scuttled out of there OR they didn't give a shit OR they genuinely didn't notice.
It's a bit grim to stare at when you're having a wee (& a general mental chunter about the minging standards of cleaning in our workplace), but no big deal. It's only blood.
Tampon, removed, parked in bin, new one inserted? Fine. No-one was harmed. A tad inconsiderate, OK, as some people might be startled to see the process & it's nice not to freak people out if one can help it, but not dirty or disgusting or unbelievable.