Hola Shirley

Taking a photo is indeed "sacar una foto" but in this text the lady is saying that she wanted to take a photo of herself with one of the authors; this is why we are using it in its pronominal form "sacarse una foto con...". So, if you talk about taking a photo of yourself (with yourself in it) we use "sacarse".

This is the whole sentence from the text so you can see it again in context:

"... y le gustaría sacarse una foto con él."

I hope this clarified it for you.

Saludos

Inma