google-hangouts
I can access the photographs that I sent through a Hangouts album but what about the photos received from my friend through Hangouts?
Where will these photos be stored?
Is it not possible to access these photos (received) other than downloading them?
Click on the Contact to open the previous Hangout you had with them. Click on the Gear and "archive" the hangout.
Go to https://get.google.com/albumarchive/
There you will found a album named Photos from Hangouts
When you click a photo in the Hangout history you will be sent to an URL that looks like https://plus.google.com/u/0/photos/albums/string-1?pid=string-2&oid=string-3. To be taken to the album just delete ? and all the characters to the right of it. The resulting URL will look like this:
https://plus.google.com/u/0/photos/albums/string-1
The photos owned by the user uploaded through Hangouts conversation can't be seen from Google Photos (http://photos.google.com), only on the owner Google Album Archive.
For each Hangout used to share a photo will be an album called "Hangout: Your Friend Name or email address ● Your Name" or "Hangout: Group name" on the photo sender account. It could be viewable by both users using the URL trick mentioned in the "Short answer" section.
1 Picasa Web Albums was deprecated on 2016. On August 2016 Google launched Google Album Archive where users could access their photos that used to be accessible through Picasa Web Albums (reference: http://googlephotos.blogspot.com/2016/02/moving-on-from-picasa.html)
Best Answer
From Hangouts Help: