I Reckon entirely upon the reader to add for himself the subjective elements that are lacking in the story.
It is true that writers have imagination. But so do readers.
I've heard it said that there are actually two stories contained in every book. There is the story that the writer wrote and then the story the reader reads.
I know this is true for me.
Have you ever read a book and then tried to watch a movie made from it. It never looks anything like I imagined, even with movies that stick close to the book. How the movie is visually made is based on the imagination and vision of someone else. And their pictures and take away info is different from everybody elses.
The reader fills in the holes and creates their own visual of a story that may differ a bit from what the writer envisioned. But this is not a bad thing.
And flash or micro-fiction leave more holes than regular story telling. Because word count is so low, fewer words are used. It's kind of like trying to get a overloaded airplane or other flying ship off the ground. It's too heavy and you have to start throwing things overboard.
In a story, a lot of description has to get tossed out. Not all of it, by any means. There has to be some setting, otherwise our characters are floating in space with nothing to attach to. But there are a lot of holes, a lot of details left out because they have to be. If they aren't, then the writing is all description with little or no action or plot.
So as flash fiction writers, we have to have faith in the imagination of the reader, that it will be strong enough to fill in the details. I find this leap of faith exhilarating