How to Save Photos from Gmail to Google Photos; With the Save to Photos feature in the web version of Gmail, you can save images directly to Google Photos without the need for an intermediary.
If the photos you receive via Gmail are first saved to Google Drive and then transferred to Google Photos, you should know that you can now do this directly without the need to save to Google Drive. Using the Save to Photos feature, which is currently only enabled in the web version, simply saves the photo to Google Drive. With this feature, you can save images sent from within the email or through the photo display window.
At the time of writing, this feature only works for JPEG images, and since it is booting slowly, it may not be enabled for you yet.
How to Save Photos from Gmail to Google Photos
Enter the email containing the photo. Hover over the photo to bring up icons in the corner. The icon on the right is the Save to Photos icon.

Click the Save to Photos icon to save the image. Click View to make sure the image is saved in Google Photos.

Save the photo through the image preview window
If you click on the image to see a preview of it, you can save it to Google Photos from the same page.
To do this, after displaying the photo, click on the vertical dot on the right side of the page and select Save to Photos.

This will pop up a pop-up notification informing you that a copy of the image will be saved in Google Photos. Click Save to confirm.

If you want to save photos received via email this way; But you will not find the Save to Photos option, just be patient and this feature will be enabled for you soon.