Well, if the item are actually on the Google account, the instructions I am including here should help you get them onto a new device. However, that said, if the items were not backed up to the Google account, and were on the lost phone only, then there is no way you can get those back.
1. Open the "Google Photos" app.
2. Tap the photo you want to save to your phone.
3. Now tap the "Options" menu.
4. And finally tap "Restore".
5. Repeat for each image.
Or, to get them all at once...
1. Log into the google account associated with the app.
2. Download all the images to an empty folder on your computer.
3. Connect the phone to the computer via USB cord.
4. Copy the images over to the phone or sd card.