Part-for-whole versus whole-for-part

Majāz Mursal and Istiʿārah: Non-similarity Relations and Their Types

RelationOriginal expressionIntended referent
Part-for-wholeʿAyn — eyeA complete watcher
Whole-for-partAṣābiʿ — fingersFingertips

Both involve part–whole relations, yet the direction of naming is opposite.

Part-for-whole: the word names a part and intends the whole.
Whole-for-part: the word names a whole and intends a part.

An adequate analysis identifies the originally named entity and the intended entity; simply noticing that bodily parts occur in both examples is insufficient.