He Who had subsisted in God-form, now is in man-form, but He is still God in man-form.

The humility did not begin when He took man-form. The humility began before that: “...who, subsisting in the form of God, counted it not something to be grasped to be on equality with God...”. There was no pride about His position. Of course, this is said quite obviously as over against Satan in the first instance, who grasped at equality with God, and that was his pride. There was no personal, self-glorifying in the position of the Lord Jesus, no self-exaltation, no grasping at something for Himself. That is where the humility of God is found. God is no vaunting, proud, self-glorifying Being.