The word μορφὴ (morphē, form, appearance) is a classical Greek noun best known from Mark’s brief mention of Jesus having appeared to two disciples in another morphē – which is expanded in Luke 24:13-35 where Luke says that Cleopas and the other unnamed disciples’ eyes were “holden” to not recognize Jesus.
And also from Philippians where Paul contrasts Christ, having been in the form or appearance of God, took on the form or appearance of a servant.
Paul may have had familial likeness in mind, between Christ and his Father, similar to the likeness of a child to parents in both mind/soul and form/appearance. – ψυχῆς τέ καί μορφῆς ὁμοιότητα
15:4 In what manner might I express the passions of parents who love their children? We impress upon the character of a small child a wondrous likeness both of mind and of form. Especially is this true of mothers, who because of their birth pangs have a deeper sympathy toward their offspring than do the fathers. (4 Maccabees 15:4 NRSV)
And it is with another family likeness that the captured kings of Midian deliberately provoke Gideon to execute them in front of the previously unhelpful men of Succoth.
Judges 8:18 Then he said to Zebah and Zalmunna, “What about the men whom you killed at Tabor?” They answered, “As you are, so were they, every one of them; they resembled (were in the essence form (morphe) of the sons of kings.”
Judges 8:18 καὶ εἶπεν πρὸς Ζεβεε καὶ Σαλμανα ποῦ οἱ ἄνδρες οὓς ἀπεκτείνατε ἐν Θαβωρ καὶ εἶπαν ὡσεὶ σύ ὅμοιος σοί ὅμοιος αὐτῶν ὡς εἶδος μορφὴ υἱῶν βασιλέων
It was by this form that Gideon knew that his brothers had not escaped at the raid on Tabor (which is not clearly mentioned in Judges) but had been slain by the two unrepentant proud men in front of him.