Here's why:
* Glass container: This refers to a container made of glass.
* Glass: As a verb, it means to rattle or shake.
For example:
* "The glass container held a delicious milkshake."
* "The wind made the window panes glass."
This is a tricky example because the noun "glass" in the first sentence is closely related to the verb "glass" in the second sentence. The difference in meaning is clear from the context.