Gmail's iOS app supports profile photos stored on Google accounts. To set this up, you'll need to take the following steps:
- Log in to the Google account you'd like to use for your profile photo
- Visit your Google Account page
- Choose the "Personal Info" tab
- From the left-hand menu, select "Profile".
- Select the pencil icon located by your profile photo
- Upload a photo of your choice from your computer.
- Once your photo is saved, open the Gmail app on your iOS device and log in with the same Google account
- If the profile photo is not appearing, try force-closing the Gmail app and re-opening it.
Hopefully this helps you get the profile photos to appear in the Gmail app on your iOS device!