Browse your system for a file to upload,
then after selecting your photo
click on the upload button.
Optional Photo MUST be added using the Photo Upload procedure in order to get it to appear on the Chatter page.
Enter the directory name of where your file is located on the upload form, but the file name must be the same as entered on the posting entry form. For example in the upload form enter C:\mydirectory\myfile.jpg. The posting entry photo name field would be myfile.jpg (without the directory location).
The simple approach is to use your mouse to browse your directory, then click on the selected file to insert the name automatically enter into the upload file name into the upload image name field.