I did a search before posting and couldn’t find anything?
Reddit search is shit. You can't appease anyone. A lot of content passes through Reddit, and some people unfortunately don't have much else going on in their life, and use Reddit for 4 hours or more every day. It will be hard to find content that hasn't been through Reddit, so don't sweat it. Trying a Karma Decay search and Reddit search using terms I thought might bring up this image again, I only found one, total, that had been posted to this sub: https://i.redd.it/8rr7kzyrvfg21.jpg
This was over a year ago. Although it was very highly upvoted when it was posted, I could see it being posted a year later. If someone saw it recently on another sub, or literally just doesn't leave Reddit isn't really on you.
It is free content that you posted, and literally doesn't cost them more than a tiny bit of finger and eye movement to get past if they have seen it before (although I hadn't seen it before; subbed for 7 months). It also fits the sub a shit load better than that COVID-19 flow chart...