Messenger chatbot > Explain me the different methods to get an attachment file received from a user

I need a *comprehensive* guide to how to access an attachment (image) sent to my chatbot in Messenger. I usually get the image from the payload (the usual way) but as I understand there are other methods to get the image - from the message id and the page inbox. I could use this to obtain better resolution images. Check this thread in Facebook Developer group to understand what I'm referring to [login to view URL] I'll consider the mission successful if I manage to get the a message attachment from the said methods (mid / page inbox). I work in node js