You are looking at the ASA logical device on the Firepower 1140. The image path referenced in the output would refer to once that is in the filesystem used by the underlying FXOS operating system. To see it you would need to "connect fxos" and change into the appropriate scope to look a the disk.
This is very very seldom necessary unless actively troubleshooting with Cisco TAC. Is there some reason why you are looking for it?
