Seemed smaller and slighter (lower camera placement makes it look much larger than it was), but it’s my best guess. It was definitely timid and not a fan of the shutter noise.
Update: Mystery solved. An intelligent A Dog’s Beach reader notes this beautiful pup is a Borzoi (or Russian Wolfhound).

I'm amazed that some dogs are terrified of the camera and some are just natural born camera hogs (or should that be camera dogs?)
Beautiful dog. Did he come with his owner or go home with you?
It is a Borzoi.
I just looked it up, Anonymous, and you are absolutely correct! Also known has a Russian Wolfhound. I know it wasn't an Afghan, but I couldn't figure out what it was. Thank you so much.
If it was smaller and slighter than an Afghan then I am going to say it is a long haired Whippet or a Silken Windhound as they are known. Russian Wolfhound's and Borzoi are very very tall so I can't see it being one of those at all.
I guess the mystery continues…
We asked the owner this AM and he said Silken Windhound which is a mix of Borzoi and Whippet.
Thanks for the info, Molly! Mystery solved.