The article was comparing Canvas to an older app, Room Capture, which required you to remain in the same location while scanning a room. Canvas does not have that limitation.
"It takes the concept of the Room Scanner app to the next level by adding the ability to walk around while scanning so you can scan a room from corner to corner. "
Canvas was designed to scan a residential-sized room in a single scan. If you wanted to scan an entire floor or building, you could do it by stitching together multiple scans with an external, 3rd party app (like a CAD system) to "assemble" the entire floorplan.