Magna Doodle has a Dreidel on it. A Dreidel is a Jewish toy; a spinning top. Traditional for the Hanukah holiday.
In the episode, Monica starts listing the names of men that Rachel has slept with on the first date, one being "Ben Wyatt." Ben Wyatt is the name of an accountant on NBC's show: Parks and Recreation.
When the gang notices Phoebe walks her bike everywhere instead of riding it, and they confront her outside of the coffee shop, Ross asks her (in a condescending tone) if she knows how to ride a bike, even though he knows that she's never owned a bike before.
When it is first learned that Phoebe doesn't know how to ride a bike, there is a Ducati motorcycle in the background. Just three episodes earlier (The One with the Nap Partners (2000)), a Ducati motorcycle was drawn on Joey's magna doodle.