Agreed. I could see how that line could be confusing. Why don't we change it for the better in that case? How about something like this:
In the example above we create a new variable sally, and assign it the value bill. Both sally and bill reference the same spot in memory. As such we can't change bill out w/ out changing Sally, specifically when a change is made to an object literal it will affect that object across the entire script.
How about: In the example above we create a new variable sally, and make it equal to bill. Both sally and bill now reference the same object in memory. Changes made via one affect both of them.
In the example above we create a new variable sally, and assign it the value bill. Both sally and bill reference the same spot in memory. As such we can't change bill out w/ out changing Sally, specifically when a change is made to an object literal it will affect that object across the entire script.