What Did the Author mean by "without seeing a brick..."?

I saw this in a description of Crowds under the Feelings Matter headline. What did the author mean by this?

“Anyone who has tried to navigate Islands of Adventure on New Year’s Eve knows that it’s not just about the wait times. On days like this you can walk to the park without seeing a single brick beneath your feet.”

We will be at IOA on New Year’s Eve and was planning on a “medium” day with crowds at a 4. Is that not the case? Is it really crowded but the ride wait times don’t indicate these crowds? Just trying to prepare since we will be there that weekend.

It means that it is so crowded that you can’t see anything under your feet. Previously in The Unofficial Guide to Walt Disney World, a park crowd rating of 1 was like walking into a store and saying hello and it echoing as no one was around, a 10 was like walking down Main Street USA and your feet never touching the ground.

Understood, thanks. I guess somehow the park is super-crowded but the wait times that day don’t correspond to the number of people in the park.