G'day Linda -- I don't see you on my list of those who already have a hat, so here's your Wizard Hat.
Full size on click.
They don't do anything, as they're just a fun thing I give to Team Aus members. (Some folk ignore them, others add them to their biography, others may choose to display them as profile images, or use them in email. Choice is yours. )
If you choose to add it to your profile's biography in any way, you don't need to upload it to Wikitree, as it's already here, just use the image code (either the {{code}} or the [[code]] will work) and the image's ID# which is WizardsOfAus-72.png (If you would like to use it as your primary image, just send me a private message and I'll send a copy to you via email.)