Q: How to open iCloud to see my pictures

If you have Settings > iCloud > Photos > iCloud Photo Library turned on in those devices, all you need to do is go to the Photos app on the device. iCloud Photo Library is used to sync photos between devices. All of your photos would be in 3 places -- the 2 devices themselves and iCloud.

You can use a computer browser and log in to the Photos app at https://www.icloud.com/ to see the 3rd copy.

More information: iCloud Photo Library - Apple Support