Sorry but your post does not make sense
Does this involve iPhtoo for the Mac (the subjedt of this forum)in any way? If so what version and what version of the OS?
iCloud is not a backup for photos - it will backup your IOS devices but the photos are not seperatly scccessable there - and the backup have nothing to do with transfering photos between devices - PhotoStream is used to transfer images - see the FAQs, sofrtware requirements, set up instructions and troubleshooting tips here
This is for my Windows 7 Computer. It used to work perfectly and stream all the photos from phone but now it has stopped about 2 months ago. Icloud is backing up fine but the Photo Stream is not streaming photos to computer. Photo Stream is clicked under Icloud and my phone shows it is supposed to stream photos but it's not been doing it for months now.