to the cloud.
Then you could upload, selectively, whenever you wanted.
However, you cannot have your cake and eat it. To make photos available to all devices, those photo's have to be uploaded from each device and then downloaded to each device.
Check out these sites to see if any are suitable for your requirements;
Where/how can I find a photo storage site in the cloud that allows me to control when photos go up and when they come down? I have a satellite ISP with a monthly data cap. Using 5 devices; iMac, MBA, iPad, 2 iPhones. The phones take pictures. I want to control when they send the pics to the cloud so I can do it when we're away from our ISP or near the end of the month. I want the pics available to the other devices but the full pic downloaded only when I ask for it. (When I browse photos in the cloud program I assume only a few hundred kilobytes for each photo viewed?)
Presently I'm using iCloud's Photo for this. It is confusing and uploads/downloads seemingly at random. If I turn it off it says it is uploading all 7k photos when I turn it back on. Is it really? My data cap is 12GB. Amazing how fast that is used up just reading the news. I've forgone UTube and videos but still approach my cap near the end of each month without using the photos.