When reading and studying (physical) books, there is more going on than just reading words on a page which also happens when reading off of a smartphone or a PC. There is spatial information—where some words appear on the page. There is the overall look and feel of the book. There is the position in the book we note by the feel of the pages of the book in our hands. All of these things can contribute to us remembering.

Computers and smartphones create a kind of unified window which makes content homogenous. Whereas you would readily be able to tell the difference between a real oil painting and a cheap print, digital technology reduces both of these to the same viewing screen. Computer technology levels everything to 0s and 1s.

It is thus unsurprising that it can be difficul tto "judge a book by its cover" with respect to lots of mass media—the trashiest of content can have the highest production value cover. High quality content might be found on a website that looks like it was made in the 90s when computers were considerably slower than they are today.