transfer data from dead phone

iCloud has two functions:

• Backup – for iPhones and iPads
• Synchronization – for iPhones, iPads, and Macs

iPhones can be set to make automatic backups to iCloud when they are connected to power, and to the Internet via Wi-Fi. I don't know if yours was. The only good way to see what is inside an iCloud backup is to restore that backup, wiping out whatever was on the device where it is being restored.

The master copies of synchronized data live on Apple's servers, in iCloud. You can see anything that made it to iCloud by using another Apple device connected to the same iCloud account, or by logging into the iCloud Web interface https://www.icloud.com/ .

So, if you were using iCloud Photos, you could see your photos now at https://www.icloud.com/, and connecting a new iPhone to iCloud Photos (under the same Apple ID) would cause the photos to appear on it. But it is too late to set up the dead phone to use iCloud Photos now, if it wasn't using it before.

Not if it's dead, no, not unless you made a backup before it died or have your data synced in iCloud.

Regards.

Glad it wasn't actually dead as you feared. Now, be sure to make and keep regular backups, either in iCloud or on your computer:

Back up iPhone - Apple Support

Regards.