Boss sends employee an email marked 'high priority' at 5:45 PM on a Friday that only contained a minion meme: 'My heart dropped. I thought the server crashed or we got hacked.'

He gave his employee a good scare.

There's a right and a wrong way to do pranks in the workplace. I think the more morally egregious workplace prank entails sending employees an email congratulating them on their hard work and offering them a cash bonus. Employees click a link in the email and are informed that they failed a phishing test. I know that phishing tests are par for the course as far as workplace pranks go, but pretending to give employees praise and more money is like dangling a carrot in front of them and pulling it away. 

If you're a manager or a boss, you know better than to schedule an "urgent" meeting with your employee first thing on a Monday morning. They're going to spend the whole weekend thinking that you're about to fire them, when in reality, you just want to talk about the project they've been working on. Now, if you are firing them, scheduling that meeting at that time is a good way of letting them know what's going to happen before it happens. But if you're constantly sending employees cryptic messages like "We need to talk" when nothing is actually wrong, you'll give everyone in your office an anxious attachment style. 

If a joke email or Slack message is objectively harmless, is there any reason you shouldn't send it? After all, if employees are so wound up they can't handle a little joke, they might need to learn how to laugh a little.