You can assign any picture to use for a contact, regardless of whether they’ve chosen one. This picture selection only appears in your Gmail interface; your contact won’t see it unless you suggest it for them.
- Sign in to Gmail at mail.google.com.
- Click Contacts.
- Find your contact by browsing your list, or by search; then, click their name.
- Click Add a picture.
- In the pop-up window that appears, click Browse, and choose the file you’d like to make the picture for this contact. Note that the file has to be a JPG, BMP, GIF, or PNG file, and click Open. Alternatively, you can add a link to a picture that’s already online by clicking Picasa Web Albums or Web address.
- Click Upload picture.
- If you’d like to crop your photo, use your mouse to drag the selection box, and click and drag on any corner of the selection box to shrink or enlarge it.
- Click Apply changes. Don’t worry — any changes you’ve made won’t affect your original file. They’ll only appear in Gmail.
- You’ll be prompted with the option of sharing this picture with your contact if you’d like to show the picture you’ve chosen for them. [source]