Here's why:
* Demonstrative adjectives point out specific nouns. They indicate which noun is being referred to.
* Examples: "this", "that", "these", "those"
* Usage: "Those shoes are beautiful." ("Those" points out specific shoes.)
While "those" can sometimes act like a pronoun (e.g., "Those are my favorite flowers."), it's primarily a demonstrative adjective because it modifies a noun.