In the diagram for the "barman" domain, each object is represented by a specific shape, size, and color to convey its identity and status. Here's a breakdown of the visual encoding:

- **Shapes**: 
  - **Rectangles** represent containers (shots and dispensers) and hands. Shots are small rectangles, dispensers are medium rectangles, and hands are small rectangles.
  - **Circles** represent shakers, which are medium-sized to differentiate them from shots and dispensers.

- **Colors**:
  - **White** indicates that an object is clean and empty (for shots and shakers).
  - Ingredient colors (e.g., **red** for ingredient1, **blue** for ingredient2) are used to fill dispensers and are referenced in the legend to identify the ingredients.
  
- **Sizes**:
  - The size of the shapes (small, medium) helps distinguish between the types of objects (e.g., shots vs. dispensers vs. shakers).

- **Relative Locations**:
  - Objects are positioned to reflect their relative locations in the domain. For example, dispensers are above shots, indicating that they can fill the shots. Shakers are below the shots, suggesting their role in mixing ingredients from the shots.

- **Legend**:
  - A legend is included to map colors to ingredients, ensuring clarity in understanding which ingredient is represented by each color.

- **Text Labels and Status**:
  - Each object has a text label for identification, and a brief status description (e.g., "clean, empty") is included inside or near the object to convey its current state.

This encoding ensures that the diagram is intuitive and that each visual element provides meaningful information about the objects and their roles in the domain.