It looks like you want to restore deleted/lost photos from Moto G3 internal memory.
Well, you can use Android Data Recovery software, which can effectively restore deleted photos from Moto G3 internal memory.
You have also mentioned that your Moto G3 is not seen, as for this case make sure:
- You have downloaded the latest version of the program. (If not then update it)
- Keep your device powered ON and make sure USB debugging is enabled
- Re-connect your USB cable to connect the device
For more information please visit: http://www.androiddata-recovery.com/blog/moto-g-data-recovery-recover-photos-contacts-sms