You can add a picture as your avatar in your user profile in Workflow. Your avatar allows others to see who you are and you to quickly see your activity in the app. It defaults to your initials until you add an image. To add an image, click "Change avatar" and select one to upload.
Choose a BMP, GIF, or PNG file of up to 2 MB in size then drag the cropper tool to the area you like best. As you drag the tool, the preview will update so you can see how your avatar will look. Click "Save" when you're done.