Checklists Tutorial - Constraints Question

I just finished adding constraints to the text label that shows an item on the Checklist screen (page 233, PDF version). Everything seems to be working fine, but I am wondering why I don’t have to add constraints to the label that shows the checkmark (or in my case an Emoji).

If some view (like that label) does not need to move or resize dynamically (based on the content you put in it), then Interface Builder will automatically create these constraints for you. So there will be constraints, you just don’t have to make them yourself.

But if you want a label that stretches to fit the width of the device, for example (since not all devices are equally wide), then Interface Builder cannot guess that this is what you’re trying to do, and you’ll have to make constraints for it.

I appreciate your tutorials and your answers to my questions. Do you have any other books/PDF’s? Thanks.