While iconicity has sometimes been defined as meaning transparency, it is better defined as a subjective phenomenon bound to an individual’s perception and influenced by their previous language experience. In this article, I investigate the subjective nature of iconicity through an experiment in which 72 deaf, hard-of-hearing and hearing (signing and non-signing) participants rate the iconicity of individual letters of the American Sign Language (ASL) and Swedish Sign Language (STS) manual alphabets. It is shown that L1 signers of ASL and STS rate their own (L1) manual alphabet as more iconic than the foreign one. Hearing L2 signers of ASL and STS exhibit the same pattern as L1 signers, showing an iconic preference for their own (L2) manual alphabet. In comparison, hearing non-signers show no general iconic preference for either manual alphabet. Across all groups, some letters are consistently rated as more iconic in one sign language than the other, illustrating general iconic preferences. Overall, the results align with earlier findings from sign language linguistics that point to language experience affecting iconicity ratings and that one’s own signs are rated as more iconic than foreign signs with the same meaning, even if similar iconic mappings are used.