I modified a few settings to make it easier to upload pics, this works both in pc and mobile applications.
few things to know:
1: there must be text in the message body of some kind. (can't be blank)
2: will not show in a 'quick reply'. has to be a full reply of new post.
3: max displayable size is 750px750px. (it will resize it down to that if its too big automatically)
you can add about 10 images to a single post. can drag/drop or browse for them by clicking bar at bottom.
hope this helps.