The rental listing you are questioning did not come from real estate broker. It looks like its a listing for Home Hunters that was syndicated through sawitonline.com. It doesn't necessarily mean the rental is not for rent - it just means that its not listed on the Garden State Multiple Listing Service which is why we, as agents, cannot access it on the Garden State MLS. You can try reaching out to Home Hunter Realty directly. Here's the site: http://www.sawitonline.com/2379483/1-bedroom-room-in-bellevi
I grew up in Belleville and my father still lives there. The picture Trulia is showing is of Route 21 near the Mill Street exit. Its not really showing a photo of a property.
Hopefully Home Hunter Realty can help. Good luck and beware of any scams or anyone asking for you to pay money online or through western union.