Thank you for your question.
The schedule what you received is just a sample, as written on it with a watermark.
The lesson you referred to is indeed shorter than 20minutes.
Within 20minutes you can work on a single lesson by listening to it repeatedly or listening to the audio other than it's main audio (dialogue, review etc. if available). Also, you can study the PDFs while listening to the main audio. Studying a lesson for at least 20minutes gives you better results.
Thank you for signing up to our program! We hope you'll like our lessons.