As I mentioned above, those are the lower resolution versions of what you have in iCloud.
"When you turn on iCloud Photos, your photos and videos automatically upload to iCloud. They're not duplicated in your iCloud backup, so you should keep backup copies of your library."
"If you turn on Optimize Storage, iCloud Photos automatically
manages the size of your library on your device. Your original photos and videos are stored in iCloud and space-saving versions are kept on your device. Your library is optimized only when you need space, starting with the photos and videos you access least. You can download the original photos and videos over Wi-Fi or cellular when you need them."
Device storage is the available storage on your iPhone, iPad, Mac, or other Apple device. iCloud storage keeps your photos, files, notes, and more, up-to-date and available across all your devices.
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iCloud Photos works with the Photos app to keep your photos and videos securely stored in iCloud, and up to date on your iPhone, iPad, Mac, Apple Vision Pro, Apple TV, and iCloud.com.
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If your photos or videos won't sync to iCloud Photos on your device, learn how to check the status of your photo library and what to do if you see a status message.
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Learn about photo storage and saving space with iCloud.
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