Adding a default survey header image or logo
Surveys by default will start with image at the top of the survey unless you have defined a logo for your account under "Settings".
To set your logo go to the "Settings > General" from top level navigation, then scroll down to the "Your Website and Logo" section. There you can upload a logo.
Once chosen the logo will be used by default in any new surveys you create from then on. A different header image can be created for any particular survey under the "Presentation" tab.