In this case it's neuter.
Usually feminine nouns end with -а (e.g. машина), neuter with -о and -е (e.g. вікно, сонце), and masculine with no vowel in the end (e.g. кіт).
With foreign words it might be trickier, but the ones ending with "-о" are usually neuter: авто, фото, сальто.
Unfortunately, it doesn't work like that :/ A similar example: автомобіль (m) --> авто (n). Words ending with "-о" are just usually neutral to us, no matter what the "parent" word was.
On the other hand, there is a short form of фотографія that's feminine: фотка :) This is more of a colloquial word, but we use it often. E.g. одна фотка.