Photos from MacBook Air not syncing to iPhone X via iCloud
I have a 2015 MBAir with OS 10.13.3 and an iPhone X with IOS 11.3.1. I've been given a folder of photos and videos and have added them to my iPhotos library. I have iCloud set up so photos as supposed to sync between my library and phone. However, the photos I've added from this folder are not showing up on my phone. Please advise.
iPhone X