When someone carries a doll in a cart, it can have various meanings, depending on the context and individual's intentions. Here are some possibilities:

1. Expression of Hobby or Collection: Individuals who are enthusiasts of dolls might display their collection publicly as a way of expressing their interest.

2. Social and Psychological Reasons: Some people use dolls for social interaction or emotional support, especially if they feel lonely or socially isolated.

3. Art and Performance: Dolls can be used in street performances or art projects. This use is about creating a visual impact and capturing the attention of the public.

4. Educational Purposes: In certain educational programs or therapeutic sessions, dolls might be used to facilitate emotional expression and communication.

5. Commercial Use: Stores or businesses might use dolls to promote products or services.