If you can't view the video (really handy by the way Appy)
In the message page click on upload picture
Click browse to find the photo on your computer to load
Click open on your picture
Once back to the upload picture click enter
It will take anywhere from a few seconds to a few min. Depending on your speed.
Once its loaded click on standard
It will resize it for you
Hope that helps.
Some folks upload their photos from an off site photo sharing service, those are the ones that don't say horseforum on the bottom
I use photobucket.com to resize mine but that's a whole other set of instructions