Google Takeout

The wife asked how to download all the photos in Google Photos at once, to store on her computer for easy viewing and backups and all that stuff.

It seems there's a Google product^tm for that.

Google Takeout^{1 2} made by an engineering team at Google with a funny name³.

References

[1] Googel Product Forums

https://productforums.google.com/forum/#!topic/photos/sLseLCfw6Pw

[2] Wikipedia - Google Takeout

https://en.wikipedia.org/wiki/Google_Takeout

[3] Wikipedia - Google Data Liberation Front

https://en.wikipedia.org/wiki/Google_Data_Liberation_Front