In the exercise of this lab, why we normalize again the user vector after we already put user features through neural network? I thought we normalize the user feature before we put them through neural netowork. Why do we need to normalize it again after neural network?
input_user = tf.keras.layers.Input(shape=(num_user_features))
vu = user_NN(input_user)
vu = tf.linalg.l2_normalize(vu, axis=1)