I am sorry to inform you that for me (and a Win 7 machine with Firefox in its current version) it is not possible to upload a photo in png format: The message "That image type is forbidden" is preventing an upload.
Have you tried using a different browser? For example, Google Chrome or Microsoft Internet Explorer? Jive may not fully support Firefox, just like FileMaker Server WebDirect does not support Firefox.
If you are trying to upload a png file to a container field you must set the field correctly in "The Inspector" : Data: Data Formatting: optimized for "images, (jpeg, png, bmp, etc)
I failed to upload a png or jpg file to this forum. As proposed by TSGAL I will try it the next time with a different browser.
Thanks for caring anyway