Intermittent grinding noise on front right break...

[machinegod]

Vehicle: 2015 Mitsubishi Mirage DE

For some reason the right front brake is making a grinding noise intermittently when I apply them. Sometimes they grind, sometimes they are quiet, and sometimes they make a sort of low tone humming noise. This front right brake has ended up doing this twice already, even after I had gotten a new brake pad and rotor. Could there be something wrong with the caliper?

I uploaded some photos. I don't have the tool to remove the caliper.

This break started misbehaving after around an estimated 13,000 miles.

I'm new to performing maintenance and repair on a vehicle.