When you researched Demanding Gods(Necrophages technology) you get the ability to sacrifice citizens to improve the approval of the city.
Issue:
City screen does not show when and how much citizens were sacrificed. It is very tedious when you have a lot of cities and can't fast see where you've already activated button(to detect this, need to look for "from sacrifice" in approval column Production)
Need to do visual difference between activated button (when citizen was sacrificed) and unactivated button, as it was realized with the activation of boosters luxury resources, for example.

You can see it if you put the mouse button two second on the population info in the city screen.

But it's clearly not easy to see. There should be a pop up who inform the player when the sacrifice effect is over, to help the management of the cities.