Yealink SIP-T29G User Manual page 59

You can also click Delete Photo to delete the photo.
Note
The phone only supports *.png, *.jpg and *.bmp format files.
You can only delete custom photos.
To change the custom photo for the contact via web user interface:
1. Click on Directory->Local Directory.
2. Click to select the desired entry which you want to edit.
3. Select the desired photo from the pull-down list of Photo.
4. Click Edit to accept the change.
Customizing Your Phone
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