I mostly use screen shots for articles like this one, but you may want to simply save a piece of information that's on your display or capture an image of your Apple Watch screen for troubleshooting purposes. Thankfully, Apple built a simple screen shot function into the Watch OS that lets you quickly capture your Watch's display and then save a .PNG file to you iPhone's camera roll.
How to take a screen shot on your Apple Watch
AS
Al Sacco