I'll give the same "introductory" explanation as the previous question you asked so that future users need to only look at this question for explanation:
Intensive pronouns and reflexive pronouns are very similar. The only difference between them is that the intensive pronoun emphasizes or intensifies the effect. Intensive pronouns aren't needed in the sentence to make it grammatically correct, it just adds a "flourish." In contrast, if you take a reflexive pronoun out of the sentence it won't make grammatical sense.
We ourselves changed the flat tire.
In this case "ourselves" is the pronoun. To see if it is reflexive or intensive let's take "ourselves" out of the sentence and see if it still makes sense:
We changed the flat tire.
It does make sense! In this case "ourselves" is not needed in the sentence. The sentence makes sense with or without "ourselves". This makes this pronoun intensive!
She herself received the best grade in the class.
Let's remove "herself" from this sentence:
She received the best grade in the class.
It does make sense! In this case "herself" is not needed in the sentence. The sentence makes sense with or without "herself". It's still clear that "she" is the one that received the best grade. This makes this pronoun intensive!
I watched myself brush my hair in the mirror.
Let's remove "myself" from this sentence:
I watched brush my hair in the mirror.
Who did you watch brush your hair? We don't know if we take away "myself." It makes the sentence unclear and grammatically incorrect. This makes this pronoun reflexive!
Hope this helped!
~Just a girl in love with Shawn Mendes