Thank you for setting me straight! Yes, Sonia is now Mr. Sonia. We've had adult male and female desert tortoises in the past but after looking more closely, I see that we have a male tortoise. We’ll move the stone tortoise to a different spot.
This is Sonia, a 32 year old female desert tortoise engaging with a stone statue of a tortoise. We have never seen this behavior before and wonder why she is doing this now. Video attached.