NB - it seems to work on some computers/ipads/tablets/phones and not on others.
Click on ‘upload attachment’ underneath your post and the ‘save draft’, ‘review’ and ‘submit buttons’.
Click on ‘add files’ it’s a red button,
double click on the image saved on your computer.
Type a comment if you want to in the 'file comment ’ box.
Click on ‘place in line’
and click ‘submit’ to submit your post as usual.