Welcome to BPO! I'm Melissa. Mom to Dazy, a 6 month old Giant Schnauzer and Ladybug, a 3 year old Miniature Schnauzer.
The little picture that posts every time you post is put up through your profile. When you click on your name after you have posted, it will take you to your profile and you can click to edit your profile. Toward the top there is an option to "browse"' and upload your own picture. Then after you open that picture there, you scroll down to the bottom and click to save your profile. Then it should be there. Feel free to PM me if you need further assistance!