This is so true. Must have someone who will recognize your dog even if she doesn’t look the same - thin, dirty, tired, stressed, maybe curled up in a ball, maybe barking her head off. Her coat may even appear a bit faded, some people might think it’s dark but not black. And a dog in feral mind may not act in recognition of you right away, she may need 10 minutes or so.
If you have a photo of you with your dog, take that with you. You might need it if she doesn’t have a chip or tags. Take your vet records showing she’s vaxxed & spayed just in case they have requirements. And be ready to bail her out, there’s usually a fee for her stay there.
If she’s chipped, they don’t always scan, don’t always have the right scanner for the chip. They may be just busy. Scanning is on the list of things to do and they get to it when they can.
Shelter helpers aren’t always the best at describing the animals they have on hand. Something about descriptions of individual animals just escapes people – they describe too generally and don’t notice details, or they just aren’t careful lookers (and don’t know they are missing things). You can ask about specific features, they look right at it and don’t see it. Even animal lovers tend to be terrible at counting the number and height of white socks.
Plus in a shelter or evacuation gathering situation, all the ones in the same general color group tend to look the same. (I think about this with my tall rangy bay TB gelding with a small star - there must be thousands of TB’s that look exactly like him).
One time I had a black cat end up at a shelter (pretty sure he got outside and pooped in the garden of a fussy neighbor). It wasn’t until the last hour the shelter was open that I thought of them and called. “Solid black cat, do you have one?” “We have 5 black cats.”
One of them was mine, I found when I got there 10 minutes before closing that night. Fortunately mine came right up to me. I recognized him and thought they all looked different, but the attendant thought they all looked the same. He probably wouldn’t have released him to me if the cat hadn’t enthusiastically claimed me before I claimed him. He hadn’t yet been chipped and I had no proof of ownership as he had been a stray that had decided to move in.