Summary
A borrowing from French.
Etymon: French image.
< Anglo-Norman and Old French himage (also imagene, imagine, ymagene, ymagine, etc.: see below), Anglo-Norman and Old French, Middle French image, ymage, imaige, etc. (French image) artificial image or representation (in solid or flat form) of a person or object (late 11th cent. in Old French), illusion (early 12th cent. or earlier in Anglo-Norman), semblance, likeness (12th cent. or earlier in Anglo-Norman), mental representation of a person or object (c1160), reflection in a mirror (c1170), appearance, shape (early 13th cent. or earlier in Anglo-Norman), symbol (c1370), figurative representation of one of the constellations, planets, fixed stars, etc. (c1400) < classical Latin imāgin-, imāgō representation in art of a person or thing, picture, likeness, death mask of an ancestor, reflection in a mirror, reflection of sound, echo, image emitted by an object and apprehended by the eyes, illusory apparition, phantom, hallucination, representation to the imagination, mental picture, description, (in rhetoric) comparison, simile, semblance, imitation, duplicate, copy, model, example, manifestation, personification, visible form, appearance, shape, in post-classical Latin also allegory, symbol (early 3rd cent. in Tertullian) < the same base as imitārī imitate v. + ‑gō, suffix forming nouns.Compare Old Occitan image, esmage (14th cent.; also imagena, emagina), Catalan imatge (12th cent.), Spanish imagen (a1250), Portuguese imagem (13th cent.), Italian immagine (14th cent.; also as image, imagine).

Notes
Several senses of the English word are apparently not paralleled in French until later, e.g.: person or thing which very much resembles another (1597; compare sense 4), literary description of something (1690; compare sense 7a), metaphor (1764; compare sense 7b).
The following quot. perhaps shows a borrowing < Anglo-Norman and Old French imagene, imagine, ymagene, ymagine, etc. (late 11th cent.) and its etymon classical Latin imāgin-, imāgō:
- ?c1225 (?a1200)
Alast to þe oðer imaines [corrected to imaiges by later scribe; c1230 Corpus Christi Cambridge MS. ymagnes] & to þe relikes luteð oðer cneoleð.
Ancrene Riwle (Cleopatra MS. C.vi) (1972)Composed ?a1200]
With the form ymagne in the Corpus manuscript compare pagne in quot. ?c1225 at pagine n. and see further S. R. T. O. d'Ardenne Þe Liflade ant te Passiun of Seinte Iuliene (1961) 169; with the form imaine (subsequently interpreted by a later scribe as a transmission error for image) compare E. J. Dobson in Ancrene Riwle Cleo. C. 6 (1972) 18 and R. Jordan Handb. der mittelenglischen Grammatik (1934) §233.
Now that we've got that out of the way...