I think the comment here by Calogero, who appears to be Reid's attorney, is that the flabby arms were something that clearly distinguished Reid from the actual

I think the comment here by Calogero, who appears to be Reid's attorney, is that the flabby arms were something that clearly distinguished Reid from the actual thief, indicative of the 40 pound difference. The implication is that the facial image was the sole similarity, and likely the only thing the police considered when jailing a completely unrelated person from another state for a week.