Q: You say that you can have unlimited brands, yet I am only able to create 10 brands?
A: Yes, this is confusing. It is due to the legacy of MyPhotoApp and the double use of the word brand. With the initial releases of MyPhotoApp, you had to use the MyPhotoApp brand mechanism so you could create different brands (color scheme, logo, contact info, look of your app). With the major redesign in Version 6, MyPhotoApp Brands are no longer needed to do that.
You can think of MyPhotoApp Brands as nothing more than something like a folder (directory) on your computer which is used to logically separate (store) your apps.
Most people only need one brand, or a maybe few MyPhotoApp brands at most to logically separate their work. But for each MyPhotoApp brand you create, you can have unlimited marketing brands (color scheme, logo, contact info, and look of your app).
To learn the various techniques of how to create unlimited brands, see the related article.
Related Article: How To Create Apps For Other Businesses