At first glance it doesn't seem like much but there are factors that might cause him some real trouble.
He posted the meme(s) in the Perry county (Tennessee) community FB group. The meme references the Perry high school mass shooting. The Perry high school shooting happened in Iowa but this knucklehead posted it in a group where it could easily be taken to mean the local Perry high school as a threat. Further, the meme has the added tag of "This seems relevant today" so it was taken as a threat to shoot up the local school. The judge seems to think it was a legit threat too since the bond was set at $2,000,000 dollars.
Personally, unless there is more too it, I think he'll get off in the end. His posts don't sound much worse than many things I've seen posted and it doesn't seem to me like a direct threat. But then, I don't live by a Perry High School
Still, sucks to be him since he's stuck in jail until at least December. Then again, he's a former cop, so I have to wonder how many other people lives he ruined by getting them locked up for months on some bullshit charge. Maybe this is just karma.