How Optimized iPhone Storage works with iCloud Photo Library

If you use iCloud Photo Library, iOS has a feature called Optimize iPhone Storage to help save storage space on your iPhone. Your original photos and videos are kept in iCloud Photo Library, and optimized versions are kept on your iPhone.Macworld reader Alexandra asks about optimized photos, iCloud Photo Library, and uploads:
I have Optimize iPhone Storage turned on on my iPhone. If I decide to order some photos from my iPhone through an online photo processor, will the photos be uploaded to the