Go to Settings,
then General Settings,
then Miscellaneous Settings
Select WYSIWYG option (top one)
Doing the above FINALLY got me to where the options & icons would appear at the top of the Quick Reply box than I'm typing in right now. Clicking on the square icon with a 'tree' inside it will get you to the photo posting function.
Nearly tore my hair out before I realized that the default settings were not allowing me to get those options, and the instructions for posting photos did NOT include the above info -- they just started out with the little tree icon info! I spent hours going through scores of postings bemoaning the same inability to post photos; FINALLY found one that explained that the WYSIWYG setting had to be selected before you'd get the little tree icon.