The parent comment meant that there is not a big difference to them on which medium (paper book, iPad, desktop monitor) they read a text, "text" is its own category instead of paper vs electronic. Similar "video" is its own category. Watching a Football game on a gigantic 60 inch screen vs on your small phone the big screen may be more comfortable, but it doesn't fundamentally change how you process the information (compared to reading what happened on Wikipedia or hearing radio play-by-play commentary.)