Hi Where to add theme description (marked with red in the image) Is it added after theme is get passed through review process or you need to add it to one of zip files at the beginning of upload ?
You add it just above the uploader, it is all part of the same form submission process. It is a common practice to write it in a text file beforehand anyway, just as a record (and incase the form submission breaks and you lose it). You don’t need to include this in the zip files at all.
You add it in the Description box