The simpler the photo, the easier it is for the viewer to focus. This is one of the problems photographs especially beginners in photography have, when you have ten subjects and all of them are competing for attention, the viewer often becomes overwhelmed and moves on; when you have a single subject with a non-distracting background, the viewer knows exactly where to look and is able to fully appreciate the shot.
Simpler photos are more impactful to the viewers because the subject matter makes more meaning to them than complicated photos. There are no additional elements that the viewer has to consider. Instead, the viewer sees the photo, is immediately struck by the content, and can build up a story along with the image. The place of getting simple photos doesn’t mean you won’t have to know basic guidelines such as composition, framing, and other rules, these basics are important for the knowledge of getting simple images. If you already have a good handle on these techniques, then aiming for simpler photos is going to be a big deal for your photography.
HOW TO ACHIEVE SIMPLICITY IN PHOTOGRAPHY
One of the major ways to simplify your image is to get closer to your subject and focus on the subject, this enables the viewers to understand the concept of the image. The second way to increase the impact of an image is through the careful use of colour. Images with simpler color palettes are often more effective. Think of the forest image in fall with a red tree amongst yellow ones, this will be more powerful than an image with a rainbow of fall color (or no color variety at all). Remember in this case though that we’re attracted to bright things first before dull things, so if you have a particular point of interest in the photo you will need to keep that in mind.
Below is a video from YouTube by Dan Reinecke as he gives a more detailed explanation of what simplicity means to photography.