Short fiction is an art form, and, frankly, you can do anything you'd like. That's part of the beauty and allure of short fiction.
However, if you want to be published in Electric Spec:
- You must have at least one protagonist. Another name for protagonist is 'main character.' I can't stress this enough. If you don't have a protagonist the reader has no one to identify with.
- You must have at least some showing. This means you cannot have all telling. Telling puts a layer of author between the reader and the story. The reader wants immerse him/herself in the story, to go on an adventure, not think: this is a clever author.
- You should very probably have dialogue. It's very difficult to have a protagonist and showing without any dialogue. It can be done, if there's only one character total in the story for example, but it probably shouldn't be.
- You must have a speculative element. We aren't called Electric Spec for nothing.
- Something needs to happen. Another way of putting this is: something needs to change in the story.