Standard veranda cabins are reported to be between 170to 175 feet square.
Concierge and Aqua cabins are 191 feet sq.
If you look at a diagram for the appropriate floors you will see the depth of the Concierge and Aqua cabins are deeper than the veranda cabin; there is a jog in the corridor at the transition.
https://www.celebritycruises.com/cruise-ships/celebrity-millennium/accommodations