You're able to brand the dashboard and, quotes and invoices, as well as your document exports in Dronedesk. So the way to set your banner at the top is top right menu "My Business" and then "Edit My Business" and then you can click on these to select appropriate sized icons so, Business Icon, and Banner and then click Save Changes.
The recommended sizea are 180x180px for the ison and banner size 436x56px. If I now go back to the dashboard, my banner appears at the top.
