You may have seen this if you have kids or are a kid at heart…
There’s a visual gag in the film Monsters vs. Aliens that highlights issues with the usability of system designs (especially if designed without the user in mind):
The Presidential war room buttons for unleashing nuclear missiles and ordering expresso coffee are exactly the same: big and red. Dialogue as quoted on Wikipedia:
[President Hathaway goes to push a huge red button; all the advisors shout for him not to]
Advisor Cole: That button launches all of our nuclear missiles!
President Hathaway: Well, then which button gets me a latte?!
Advisor Wedgie: Err, that would be the other one, sir.[The camera zips back to show an identical button next to the first one; the President pushes it and serves himself a cup of coffee]
President Hathaway: What idiot designed this thing?
Advisor Wedgie: You did, sir.
President Hathaway: Fair enough. Wilson, fire somebody!
Wilson: Right away, sir.