Why does Photos file on Mac size increase as Photos Library uploads
I have finally decided to upload my Photos from my iMac to iCloud. I have 12,000+ photos loading now. When I started on the 14th, my Photos file was 59G. When I checked Photos preferences today it says 29 of 59G has uploaded. (Hey, not the fastest connection...). I then looked at my Photos file in my Home folder and it has increased to 89G. Why is this?
As always, thank you to all who will help and have helped in the past.
Fred