Here's how it's typically used:
* "As a box of chocolates": This implies a variety or assortment of something. For example, "The new store carries a wide variety of styles, it's like a box of chocolates."
* "As a box of rocks": This implies something is boring, dull, or lifeless. For example, "The meeting was as a box of rocks, nothing interesting happened."
* "As a box of kittens": This implies something is cute, playful, or adorable. For example, "The baby animals were as a box of kittens, so tiny and cuddly."
The specific meaning can vary depending on the context and the type of "box" being referenced.
It's important to remember that this phrase is idiomatic, meaning it's not literal. It's more about the feeling or impression conveyed rather than a direct comparison.