Various words referring to pictorial representations of objects or ideas often have precise connotations. Here are many words conveying subtle shades of meaning about signs and symbols.
1. Attribute: an object, especially in representational art, signifying a person or place, or authority (also, a characteristic or quality or a word describing a quality)
2. Badge: a sign symbolizing achievement, authority, or membership
3. Cachet: a seal used to denote official approval, or an indication of prestigious approval (plus additional meanings, including “prestige”)
4. Coat of arms: a heraldic symbol or combination of symbols, or one or more symbols serving a similar function (also, a garment on which such symbols are employed)
5. Cognizance: a distinguishing sign (plus additional meanings)
6. Colophon: a printer’s or publisher’s symbol (also, an inscription providing information about the production of a publication)
7. Crest: see “coat of arms” (plus additional meanings)
8. Cryptograph (and cryptogram): a sign with hidden meaning or significance (also, a coded message)
9. Device: a heraldic symbol (plus additional meanings)
10. Emblem: a symbol associated with a particular thing or concept
11. Ensign: a sign of authority, or a sign or a flag (also, a military rank or someone holding that rank)
12. Hallmark: a mark signifying approval or authenticity (also, a distinguishing feature or trait)
13. Homologation: official approval or confirmation
14. Icon: a symbolic image
15. Impresa: a heraldic symbol
16. Imprimatur: approval, license, or sanction, or a mark thereof
17. Insignia: a sign of authority, honor, or rank
18. Logo (also logograph and logogram): a statement or symbol of identification, or a motto
19. Monogram: an identifying sign often consisting of conjoined initials
20. Pictograph: a symbol in a pictorial system of communication
21. Rune: a particular type of alphabetical character later associated with magic (plus additional meanings)
22. Stamp: a distinctive character, indication, or mark, or a lasting impression (also, the act of stamping or the device used for stamping, as well as a piece of paper fastened to another object as proof of payment)
23. Token: an expression, sign, or symbol (also, among other meanings, a characteristic, or a keepsake)
24. Totem: an object or symbol representing kinship
25. Trademark: a word or other symbol applying to a product or service (also, a distinguishing feature)
I would include both signal (“a sign of a particular situation”) and its literary cousin sigil as well. Both are certainly at least as “pictorial” as, say, homologation