Review details on this feature release in the following blogs and video tutorials:
Thank you,
Audrie
This is the current state as of end of year 2017. Here are a few videos that expose this functionality:
https://www.youtube.com/watch?v=3dCwg6wtViI
https://www.youtube.com/watch?v=rgjC12rn-CI&t=23s
Thank you for your continued feedback and support,
Audrie
If you open the data panel from within the app, you'll see the "Edit Data" link under the name of the data source from SharePoint. With customize forms you'll also see the full link in the back stage of the app (using the File Menu).
Let me know if this works for your scenario.
Thank you,
Audrie
Thanks so much for sharing this with us! I've seen your content before and it's great!
If you have not already, could you please join our team of Community Bloggers!? All you have to do to get started is to go to the link below, look over in the right navigation area, and click the "Message Admins" button to request to be a blogger!
https://powerusers.microsoft.com/t5/PowerApps-Community-Blog/bg-p/PowerAppsBlog
Looking forward to seeing more from you!
Audrie
We have started working on this, but this is complex as by default SPO lists do not have a concept of images stored in them. This is the top item on our SharePoint connector team and we are actively working on it.
Sadly, don't have a timeline due to the complexity of the problem.