For the WordPress.org plugin repository, you need to create:

1. icon-128x128.png - Used as the plugin icon
2. icon-256x256.png - High-resolution version for retina displays

These should be placed in this assets directory.

Design tips:
- Keep the design simple and recognizable
- Use a consistent color scheme with your banner
- Ensure it looks good at small sizes
- Use a transparent background if appropriate