Sforno on Exodus 28:27/ספורנו על שמות כ״ח:כ״ז

1ממול פניו, the letter מ at the beginning of the word ממול means that it is not to be at the level of his face but below, i.e. where the ephod’s sash is located not where the shoulder pads are located above his chest.

2לעומת מהברתו, on the level where the ephod’s sash is tied.