Hi! Imagine yourself at boyhood. You are 13 or 15 years. You like her, but you are embarrassed to ask her to give you her picture. And here you dared to ask her. Then you can say: "Дай свою фотку"
If you say the same way at middle age, most likely, you live with ma in her home and continue playing video games.
A word фото you can use for typing a message, because фотография is so long))) If you say like this it will not be mistake, but will sound it a little bit affected. (чуть странно или манерно)
Фотография is ok