I can't imagine you imagining you have no imagination!
Only very recently have I learned that even my children and other family members do not have fictional dramas unfolding in their heads. What on earth do people think about then, when during hours of chores and mindless tasks? You don't have to write fiction though to be a writer. Your photos and captions/commentary show that you're a keen observer, thoughtful, and good at capturing images - skills all writers need. Now stop selling yourself short and know that you've earned your place among all the bloggers!