A URI that can be used to retrieve a thumbnail of the contact's photo. A photo can be referred to either by a URI (this field or Android.Provider.ContactsContract.ContactsColumns.PhotoUri) or by ID (see Android.Provider.ContactsContract.ContactsColumns.PhotoId). If PHOTO_ID is not null, PHOTO_URI and PHOTO_THUMBNAIL_URI shall not be null (but not necessarily vice versa). If the content provider does not differentiate between full-size photos and thumbnail photos, PHOTO_THUMBNAIL_URI and Android.Provider.ContactsContract.ContactsColumns.PhotoUri can contain the same value, but either both shall be null or both not null.
Type: TEXT