That is the orbital prediction at the estimated time of reentry. They take where it is right now projected about 3 days out, and show us 6hrs before and after.

That is the orbital prediction at the estimated time of reentry. They take where it is right now projected about 3 days out, and show us 6hrs before and after. LEO takes around 2 hrs or less to circle the earth. This will change. If there is more drag then expected, or any one hundreds of different things happen, the reentry time will change, and then the predicted area will change.