A.T. Robertson Commentary Mark 16:12

"And after these things he was manifested in another form unto two of them, as they walked, on their way into the country." — Mark 16:12 (ASV)

After these things (μετα ταυτα). Only here in Mark. Luke tells us that it was on the same day (Luke 24:13).

In another form (εν ετερα μορφη). It was not a μεταμορφωσις or transfiguration like that described in 9:2. Luke explains that their eyes were holden so that they could not recognize Jesus (Luke 24:16). This matchless story appears in full in Lu 24:13-32.