The sublexical structure involves features of sign articulation which are handshape, movement, location, and orientation. These phonological features are not about all precise details in articulation i.e. phonetics, but about recurrent properties across various signs regardless of meaning.
Certain iconic signs have a dramatically different sublexical structure than other signs, such as the manual alphabet [Lexicon - 2.2.2.] or lexicalizations of classifier constructions [Lexicon - 1.2.1].