I think the commenter refers to the fact that in Julia, code is data, even if it is not represented as lists. This allows the existence of macros, which are syntactic sugar to functions modifying code. Also that most (all?) lisps have multiple dispatch as a fundamental part of the language, and Julia does too.
Every time this pops up, I feel compelled to point out how different Julia macros look like from regular Julia code, especially once the macros get complicated.
"Code as data" is not quite the same thing as homoiconicity, which I feel is Julia's missing piece.
