A little of each. One T has cowl lights which would suggest a non starter car. The other would be battery equipped. The Harley on the right has an acetylene headlight and an "M" Prestolite tank mounted on the handle bars. (Model F) It would have had magneto ignition. The others with electrics lights and a battery. (Model J) It was an era where people were making those choices. Great picture. I,m guessing 1920 + or -.
Whenever I see a sidecar like that I think of Harpo.
They aren't dressed for extremely cold weather so it's either fall or early spring, or the tree is dead.
Anyway, that's a neat picture.
The Prest-O-Lite tank on the motorcycle handlebars is an "MC".