What to do when a stranger human is ignoring you?

As you know, we make frequent trips to the beach so that the dogs can feel the sand beneath their toes and the wind in their hair.

Recently we went to the beach in the late afternoon. There was a strong wind blowing and kicking up the sand. It was like being sandblasted in the Sahara. There weren't many other doggies or humans there due to the conditions.

The lack of the usual hustle and bustle meant that Barbie was paying particular attention to a lady who was walking along at about the same pace behind us. For some reason we stopped - I think Bender lost his ball - and the woman walked past and strolled up the beach. Barbie did one of her many zoomies along the beach, but instead of turning around and coming straight back to us, she trotted along behind this lady.

Barbie: Hello there. Excuse me. Hello?

(lady continues walking)

Barbie: (trots a bit faster to be alongside lady) excuse me - would you stop to admire my beauty for a moment?

(lady continues walking and does not even turn her head)

Barbie: (stops) well, that was disappointing. Oh, I have an idea!

(Barbie runs up behind the lady and rams her right in the middle of her butt)

Lady: (flails her arms around) oooooooooh!

(Barbie does it again, but this time lighter)

Me: Laughing uncontrollably, Barbie! Come back!!

Barbie: Oh really, why do I need to.... ohhh OK.

I wonder what compelled Barbie to give the arse headbutt - I think it must work with dogs?