Shadow Naoto represents the reversed Fortune Arcana. The reversed Fortune indicates mounting misfortune and a feeling that everything possible is going wrong. It also reflects one who is egotistical. Naoto's feelings of misfortune partially reflect the case (new twists eliminating plausible theories, one after another), but are mostly stemming from her growing frustration at being treated like a child. The less she feels she is taken seriously, the more she becomes obsessed with the case and the more she tries to prove her competence, which only leads to her being taken even less seriously. She denies she is, in fact, still a child (causing the Shadow to wobble between childish immaturity and rash, impassioned accusations of Naoto's true character) and her tendency to shun outside help. In its most human form, Shadow Naoto is seen crying like a child, opposing Naoto's sober and secure nature, not letting her emotions get the best of her. When Naoto precedes to leave, it begs her to stay, almost like a neglected child. Furthermore, when Naoto accepts her Shadow as a part of herself, it states "When I grow up, I want to be an awesome hard-boiled detective!", giving further sustenance to the Shadow resembling the inner child Naoto has shunned.
for the last one while I'm not sure if it counts as a shadow, I'm still putting it here
Although Kunino-Sagiri appears as an unspecified arcana (if any), he can represent the reversed Justice arcana. The reversed Justice is essentially injustice; a wrong perception of what is righteous and wrong. Clearly Namatame thought what he was doing was right, and thus developed a messiah complex believing his actions were heroic and righteous, rather than actually putting the people he "saved" in mortal danger.
He shows a little resemblance to the figure of the Christian Jesus, who people refer to as "The Savior".
Well that's all of them however feel free to make your own theories