That's normal.
You do need to remember that the Ecoboost does sit slightly higher than the GT model of the same year on spec. (Ground to top of roof height).
Also, that gap will close slightly as the springs bed in. Your car is still very new in this regard.
What you don't want to do, is lower the car by using shorter springs or coil-overs... If it's a road-going car and not a track car.
Lowering the car, only changes the finely tuned suspension, and many times creates a worse handling car unless you do the job properly, know what you are doing and change other suspension geometry.
Not worth it purely just for "looks" IMO.
You like me drive on Aussie roads... Not well-maintained German Autobahns.
I would not want my Ecoboost any lower with the number of speed humps, potholes and high parking kerbs I have to contend with my Stang being a daily driver.
The number of people I see with lowered Mustangs that have scrapes and damage to the front spoiler is ridiculous.