When people say "flashy," they usually tend to mean dangles and sick dekes and plays where one guy burns the entire opposing team and so on. Guys who get along mostly on stickhandling and speed.
Crosby is capable of that stuff, but he doesn't do it as much as he did when he was younger. Combined with his use of board play/puck protection skills to do most of his damage, it means people who don't watch him play all the time don't always realize just how many crazy things he can do.
Sometimes it takes a stretch like this past week and a half, with Crosby just deciding to play experimental, concept-album style levels of insane hockey, for people to remember exactly the depth and breadth of his skillset. There are individual players that are better at certain aspects of Sid's game - people who are slightly faster, maybe a bit better defensively or on faceoffs, better shooters. But no one is as good at as many different things as he is, and there are certain things - hand-eye and midair shots like we've seen recently - where he just does things you've never seen before.