Muhafhafah evokes a fine and lightly built figure. Mufāḍah is associated with breadth or bodily fullness, and ghayru negates that contrasting description.
The effect is twofold: the poet positively names delicacy and then negatively excludes the opposite quality. This combination of affirmation and negation of a contrast sharpens the impression of proportion.
WordMeaningRhetorical role
MuhafhafahSlender, lightly builtPositive description
Ghayru mufāḍahNot broad or bulkyExclusion of the opposite