I don't understand this. Lets say I have a 15gb drive limit and 10gb of photos. After this change, will I have 10GB of photos in Google Photos and 10GB of photo

I don't understand this. Lets say I have a 15gb drive limit and 10gb of photos. After this change, will I have 10GB of photos in Google Photos and 10GB of photos in Google Drive, putting me at 20GB total? Or do the duplicated photos not count towards storage limits? edit: "If you use Backup & Sync to upload photos and videos to Drive and Photos, it will upload a copy to each service, but it will not take up duplicate storage." I assume this applies here too