To load photos from storage on your computer...
First open a reply box.
Look below it and choose 'attachments'. (Next to 'options')
Then click on 'upload a file'
That will take you to the choices of storage on your computer.
Choose the area where the pictures (called files for some reason) you want are stored then choose the photos. It might say 'done' or' add' or something for you to indicate that you are done choosing them.
That
should take you back to the reply box automatically and you will see the photos listed below the text box (not in it).
Then complete your text and submit.
If nothing to say just put a period or something in the text box as it won't post empty.
Maybe this will get you there?
This
thread might be a good place to practice