There’s a lot of chatter out there on the interwebs about Dom’s real totem. Some say that his wedding ring is his totem. Others say that his children’s faces are his totem. One thing that all this has in common is that his wife’s spinning top totem seems like kind of a bad totem.
The point of a totem is to make sure that you keep track of reality. Dom tests Ariadne by trying to trick her into giving him her totem. He approves when she refuses. You need to keep your totem a secret because you want to make sure that you don’t get lost in someone else’s dream where they have replaced your totem with a fake version. This is the mentality of a dream walker who is expecting adversarial attacks. A secret totem will protect you because your attacker will not know the secret property of the totem. If you are in a hostile dream your totem will lose its secret property because your attacker will not know what that property is. So if your totem does not have its secret property then you know you’re in someone else’s dream.
Mal’s spinning top totem only has it’s secret property when it is in a dream. In reality the top will topple. But think about what happens if Mal is in a hostile dream. The attacker will not know the secret of the totem and when Mal spins the top it will topple even though she is in a dream. This is a totem that was made by a dream walker who does not expect adversarial attacks. Mal made this totem so that she’ll know if she’s stuck in her own dream (or a dream of a cooperative dream walker). Mal always expects her top to spin forever. And it will if she’s in a dream she controls. It won’t if she’s back in reality.
This makes sense though. Mal came up with the top back when she and Dom were experimenting with dreams in a friendly context. Dom came up with secret totems after joining the underground world of corporate dream espionage and he realized there could be hostile dream walkers and that he might be a target.
So why does Dom still use Mal’s top. Dom and Mal never woke up from limbo. It really is infinite down there. And Dom is trying desperately to stay out of any dream that Mal controls.
We don’t know how Dom and Mal setup the initial dream within dream scenario that led them to limbo. But it was probably by alternating between who was dreaming. After all this was how they did it in the movie proper. They always used a different dreamer when going down a new level. So I’m going to suggest that Mal was the dreamer in control of limbo. Dom would be in control of the dream one level up. And Mal the one above that. Dom tells Ariadne that he couldn’t stand living in limbo. But that’s because Mal was in control of it. In the flashback/story that Dom tells Ariadne, Mal claims that Dom is in control of the dream they are in but he can’t control it because he doesn’t know he’s dreaming. He does know he’s dreaming, but he’s lying. He knows if he and Mal kill themselves that they would just drop into another dream. This time with Mal in control. Mal kills herself and goes up another level. Dom stays.
Dom said his mission was to get back to his kids. But we don’t learn about that until later. What we learn right off the bat is that Dom has a figment of Mal that is tormenting him. This story is about Dom trying to rid himself of Mal’s influence. The story starts with a top spinning and then we’re introduced to Mal. The story ends with Dom walking away from the same top that represents Mal’s influence. This is why Dom is always checking the spinning top. He knows that if the top doesn’t fall then he’s in a dream controlled by Mal. Or the figment in his mind that represents her. His goal is to create a sub-dreamverse that is completely isolated from Mal and where he has total control.