Do you know what program the technician used to recover the data?
What is the format that you don't recognise?
When you explore the separate HDD 1 TB what do you see displayed? Is it a long list of files or folders? How much of the drive has been used (rightclick and choose Properties) this will confirm or not if there is any data on it.
It is possible that the recovered pictures no longer have their original names and are just numbered. What is the file ext for the files? (.jpg or something else?)