Subtask is currently in development and will be on the next version (1.5). Below is the screenshot of how it runs currently :
You might see above that subtask view has it's own column header. It's because you can arrange it's layout independently of the main taskview. You might have usage pattern where your subtask will always have the same folder and context as it's parent so you don't want to see those columns on subtask view. In that case, you can just hide it and gave your subtask view more space for other information.
Below is the screenshot of how subtask view layout can be independently arranged :