One of the quickest and easiest enhancements you can make to your UPK outputs is to add your own logo. Once selected (and you only select once) this same local replaces the Oracle item in the header of the player package, and in all the published documents.
To add your own logo you need to first make one. According to the upload screen this should be no larger than 230 x 44. Additionally, while it does not say this anywhere, use a .GIF format file. The Player Package, once published, always publishes your logo in that format, and its conversion tool is not great. My first efforts used a .PNG image, and I ended up with some peculiar dithering, as shown here.
Note you don’t have to upload the image to your library. When requested it can simply be loaded from your computer.
For bonus points you can also update the other Oracle-branded image that appears in the player package heading.
However there does not appear to be a simple way to do this in advance. Instead you need to publish the package, and then go looking for banner_image.png in the img folder:
The default image is 525×54 so aim to replace with something the same. It is also right-aligned by default, so give thought to how the left-hand end will blend in with the background.