Either that or look at the plastic push clips that hold cover to the fender inside trunk. They look to be relaxing (at least the back one) in the pic. Those pushpins are Ford's best friend at assembly time but very often out in the field they and parts they're holding relax from heat and vibration to make for a need to tighten things up. Sometimes just changing pins won't work, I've had to resort to inserts (expanding nuts?) similar to sheetrock mounting stuff to use a bolt to positively hold part in place.
Some jerk kissed my son's '12 Nissan on opposite side to fold in the bumper cover inside out right there at your pic location, his crack was much wider. I had to remove bumper cover and using a heat gun push the cover back out and then had to replace the pushpins at fender to bumper with rivets drilled inside. The pushpins had yielded the holes too big from the stress. When all done you could not tell car was even touched since it was new and paint very flexible to be able to take me manhandling it. $1000 damage fixed for free...........of course I made him buy me steak dinner that nite.