You were just reminded in the scene with Miles that they have all been back through time, left the Island, etc.... I believe that's why Miles had that line to Ben, "I lived in these houses 30 years before you did, which was really last week, or something like that." (paraphrase)
This line was said to make sure the viewer remembers what we were being shown was no flash forward--all of our Losties have gone through the trials they did to RETURN to the Island with Locke in the coffin. Do not mistake any of this for a flash sideways.
cheers
*Des8