The early days of drive in was waiting in your car in the parking lot and wait for a server to come out to you to take your order. Then they return to your car with the food for you to eat in your car in the parking lot. They often had trays that hooked into your window or trays that would sit in your lap to eat from. This food was diner style food and wasn’t quick to make like fast food today is.

These styles of restaurants fell out of style when cheap quick fast food came along and many of these old style restaurants went under and disappeared.

The ones that didn’t line. A&W adopted the eat inside model with a drive thru window for pickup.

Then there are chains like Sonic in the US that have this old style pull up parking and a drive thru.

I assume this Chick Fil place is doing something similar or they are just delivering food during the pandemic to people that preordered ahead of time in the rain.