Yes. During the remix workflow you are given the option to customize your own cover. You can either use our template or upload your own cover. If you use our template, you are required to add a title, and optionally a sub-title. You can also choose the banner cover. Our template displays thumbnails of the parent ebooks from which your content was sliced from in a grid pattern.
You can also choose to upload your own cover or cover image. Below is the UI for the cover design workflow.