We convey meaning using words, but it doesn't have to be that way. They may have sounds that map directly into spacial descriptions in a way that light works for us.
Yeah, for whales by mimicking sonar (caveat emptor).
In Signed Language you can point into a 3D space. If you define a mapping of the world into the 3D space available to Signed Language then you have the world at your fingertips.
I love sign language for it's "pronoun" system and spatial features, but the reality is we could just a easily "annotate" spoken english with similar spatial context, sign language just does a good job of teaching all parties how to do that be default. By not teaching ASL to everybody who speaks english, we are really missing out on more bandwidth (for detail and redundancy) in communication.
In Signed Language you can point into a 3D space. If you define a mapping of the world into the 3D space available to Signed Language then you have the world at your fingertips.