can I attach Image to a task ?
unfortunately, it's not possible right now, but thank you for your suggestion, we appreciate it and will consider adding such option in future development. Feel free to add for this request to our Votebox: http://todoist.com/Vote/
For now, as a workaround, you could use one of your browser plugins (Todoist for Chrome, Firefox or Todoist Anywhere) to use the "Add website as a task" option. If you open an image in your browser, you could add a direct link to this image (if it's stored on the internet and not locally).
Alternatively, if you're working in a team, you can check out Wedoist ( https://wedoist.com ) - our team-based project management which allows storing files (incl. images) in your projects and attach them to tasks or status updates.