Yes! How you'd like to do it depends how your landing page/template is coded.
If the header image is editable within the landing page editor, then that's an easy way. Just go into the Marketo editor and change the image.
IF, on the other hand, you have the header image as CSS within the template itself, you can accomplish this change by putting in a token within the CSS of the template.
<style>
.banner { background: url( {{my.contentBanner:default=http://website.com/default-background.png}} ); }
</style>
Then you're able to define the token at different levels depending on the campaign. We used this for one of our clients, and it was incredibly helpful. We set up a default image for the header in the template token, and then if we decided we wanted a banner with a more appropriate image, we could change it with a token at the campaign level.
Using a token to define this opens up a lot of possibilities for the future, such as segmenting based on location—as our clients grow internationally, the images can be swapped easily to provide localization.
Best,
Edward Unthank SEO/Web Specialist
Yesler