From the article:

Some of you use Google Takeout to keep a local copy of your photos and videos. We’re excited to share more information on Incremental Takeout for Photos, a feature that makes exporting your photo library faster and more efficient.

• Full initial export: Your first scheduled export contains all your selected photos and albums.

• Future exports: The next exports in your schedule include items uploaded, backed up, created, or edited since your last successful backup. This saves you time and storage space.

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Update 6/3/26: We see you're as excited about this as we are! Please note that this feature is currently rolling out. If you don't see the incremental export options in Takeout just yet, hang tight! It will be hitting your accounts over the coming days/weeks.