When asked to proofread something again and again, eventually we stop seeing what we already believe to be there. In other words, the very obvious mistake can hide in plain sight and come back to haunt us. We’ve all been there!
A recent and humorous example caught my attention last week, when the Vermont police were found to be driving squad cars with a hidden epithet. Prison inmates make the decals affixed to up to 30 patrol cars, and they had hidden a pig in the artwork files without anyone noticing. You can probably spot it quicker than the police who look at the decals everyday.
Personally, I think the pig is a lot cuter than the three strange animals to the left. What the heck are those things supposed to be?