It turns out that a picture isn't exactly worth a thousand words as the old adage says. In fact, it's worth exactly 84.1 words, which is the number of words it takes people to describe an image, according to cognition expert Alan F. Blackwell. That said, visuals are much more memorable than words, which is why it's best to take care when choosing one.
There's a great article on thenextweb that describes this in more detail, but here are the 5 qualities of a memorable graphic in a nutshell.
1. Harmonious colors. Colors schemes that are natural and work together are the most memorable.
2. People expressing emotion and interacting. Some objects can also be memorable, but landscape images are largely forgettable.
3. Prior knowledge of the subject. Aesthetically pleasing images aren't very memorable.
4. Infographics are memorable, but graphs aren’t. Musicians aren't likely to do many graphs though, and that's a good thing.
5. Multiple images reinforces the point. In other words, a variety of images is better than just a single image.The graphic on the left incorporates 3 of the 5 qualities just mentioned. The colors are harmonious, we all know what a brain looks like so there's prior knowledge, and there are multiple images (the brain overlaid with the skull x-ray). It's perhaps not the best example of the ideal graphic, but it does capture your attention.
This is something that I'm going to be placing more emphasis on in the future, and perhaps it's something that you should consider in your posts as well.