You bet it will! You'll remember my two GPOs that contain conflicting settings; one is setting the desktop wallpaper to a blue number 1, and the other to an orange number 2. Prior to enforcing anything, my Blue 1 GPO was linked at the root of the domain, and my Orange 2 GPO was linked at the Accounting OU. Since OU links process after domain links, my Accounting computers were all receiving the Orange 2 wallpaper setting.

However, now that I have right-clicked on my domain-level Blue 1 policy and chosen to enforce it, my Accounting computers will all change over to the Blue 1 desktop wallpaper. We see an explanation as to why this happens if we click on the Accounting OU and then navigate to the Group Policy Inheritance tab. Here you can see that Set Desktop Wallpaper to Blue 1 (note how it is the one linked at the domain tier) has jumped to the top of the priority list because it is being Enforced: