The two terms of simile are not merely interchangeable grammatical constituents. The mushabbah is what the speaker seeks to characterize, while the mushabbah bih is the familiar or striking model used to illuminate the quality.
In “The student is fresh like a flower,” the student is the subject and the flower supplies the comparison. Reversing the imagery—“The flower resembles this student's face”—creates a different rhetorical direction even if the same ideas recur.
The formal topic of reversed simile (التشبيه المقلوب) is treated later. Here it is enough to see that similarity of meaning does not erase differences in the terms' communicative roles.