#28: Batman: The Bat-Signal
One of the most famous images from Batman is that of the Bat-Signal, a massive light that can be shined on the clouds at night to summon Batman when the city needs him. Now, this probably comes from the fact that the Bat-Signal first appeared in 1942, and in those early days, there wasn’t a great way for the police to contact Batman quickly.
But in-universe, what’s the point? By the time Batman sees the light, rushes over to see who turned it on, and finds out what happened, the crime is probably over. So what if it’s not to summon Batman at all? What if it is to remind evildoers that Batman is out there and they should probably stop doing evil before he catches up with them?