If you ever designed a web page, you know that you are supposed to test it on different browsers, optimize for mobile displays and if you can, view it on multiple monitors (to see if your colors work, for example). Concerns are similar for the visualization you are about to create. A lot of your design decisions need to take it in consideration if the visualization will be shown on multiple displays and whether these will be asynchronous (i.e., will you put it on the Web), whether you imagine this being seen on a mobile display (phone, tablet), whether it may be printed (if yes, should it be optimized for black and white?). Sometimes the visualization is meant for a single person or group, and it will live on a lab’s wall. But even then you may need to think if the monitor may be stereo, tiled or multi-touch. Each hardware has a limitation (color configuration, screen size..) and what you see on your screen will not “just work” on another.