When a statute presents a general category and says that category "includes" some specific examples, those specific examples are deemed to belong to that category for the purpose of the statute.
Statutory definitions are also used to expand the usual scope of a word or expression, for example:
In this section,
"fish" includes shell fish, crustaceans, and marine mammals;
...
In these examples, the statutory definition enlarges the ordinary (or technical) meaning of the defined terms by including things that might normally be thought to fall outside their denotation.
(Ruth Sullivan, Statutory Interpretation, 3rd ed. (2016), p. 81)
And in the U.S. textualist context:
Individual statutes often contain definition sections giving ordinary words a limited or artificial meaning.
(Antonin Scalia & Bryan A. Garner, Reading Law: The Interpretation of Legal Texts)
But Ruth Sullivan notes, "statutory definitions do not necessarily lighten the interpreter's load. Many simply add to the ordinary or technical meaning of the defined term, which must still be determined in the usual way" (p. 82).
There are many other competing canons and principles of interpretation. The fact that an unexpected example is listed may be read to imply that the general category is actually broader than its common meaning would normally convey. One cannot answer interpretation questions in the abstract. In canada, the current approach to statutory interpretation is that:
Today there is only one principle or approach, namely, the words of an Act are to be read in their entire context and in their grammatical and ordinary sense harmoniously with the scheme of the Act, the object of the Act, and the intention of Parliament.
Rizzo & Rizzo Shoes Ltd. (Re), [1998] 1 S.C.R. 27 at para. 21
This approach has not been as universally accepted in the U.S., but given the inherent tensions between various canons of interpretation (same word–same meaning; expressio unius; etc.), it is similarly not possible to answer interpretive questions in the abstract. In all but the clearest cases (and even these would only be clear in context), to make any meaningful argument, one would need at least the full statute for examination.