Hola William
They are optional, however, in this lesson, as the purpose is to show how to conjugate reflexive verbs in the present, we state the pronouns so it's clear who the subject is each time. In addition, you could for example get confused with a sentence like:
Se lavan por la mañana.
Here, without the pronoun, this could be ellos/ellas or ustedes.
Se ducha temprano.
Who is it here? ella, él, usted?
I hope it clarified it.
Saludos
