Lights in the aisle will guide you towards an exit.
I've sat through a lot of safety briefings (for commercial scheduled passenger flights) and always found this sentence especially uninformative. Usually the cabin crew pantomime will include some vague gestures towards the floor of the aisles at this point, but even with airlines that use pre-produced videos for their briefings it seems that the video never actually shows those guiding lights in action.
Are they moving dots of light in the floor that chase towards the nearest exit row? Are they fixed lights that are shaped like arrows, pointing to the exits? Or just a strip of light that will tell me, "here is the aisle", but I'll need to figure out by myself which way along it to crawl?