The OneStep+ is an analog camera: it doesn't have a sensor and it doesn't have a screen either. Each Polaroid photo made with the OneStep+ is an original, with no two the same. If want two copies of the same photo, you'll have to ask your subject to stand very still while you hold your breath and try to re-create the exact same photo twice in a row.
What you can do is scan your Polaroid photo using the Polaroid app Scanner. This allows you to share it with friends, post it on social media or even send a copy to the print shop if you like.
More information about the Polaroid app Scanner feature can be found, here.