Also, having been there recently, the taxiway is longer than the runway, the same width (as previously mentioned, it's intended to be used as a runway), and quite a lot brighter as it's not covered in rubber. It's contrast in most lighting conditions makes it more obvious than the main landing runway, especially during a circling approach. Also, last thing promise!, the landing runway is closer to the passenger terminal than the taxiway, in most places the parallel taxiway (or emerg runway) are closer to the civilian apron (logical airport layout). It all adds up to a potential trap in developing a mental model of what you're looking at. As we all know, it's hard to change that model even when presented with evidence to the contrary at a late stage, such as runway markings, approach lights, PAPI's etc.. All good briefing points when having your chat before TOD.