public static com.google.cloud.videointelligence.v1p3beta1.FaceDetectionAnnotation
      getDefaultInstance() {
    return DEFAULT_INSTANCE;
  }
<pre>
The thumbnail of a person's face.
</pre>

<code>bytes thumbnail = 4;</code>

@return This builder for chaining.
java-video-intelligence/proto-google-cloud-video-intelligence-v1p3beta1/src/main/java/com/google/cloud/videointelligence/v1p3beta1/FaceDetectionAnnotation.java