Difference between enabling Time Machine's "Encrypt Backups" option, and encrypting from Disk Utility? I'm setting up Time Machine backups on a new external hard disk.

I chose to first encrypt the disk via Disk Utility:


But I also see these options:


Is there any difference between an "Encrypted" format via Disk Utility and selecting "Encrypt backups" in the Time Machine preferences? What happens if I do both? Or if I encrypt with Disk Utility, but then don't select "Encrypt backups"?
Aha! The answer comes when you try to deselect the "Encrypt backups" option:



So it appears they are one and the same.