With Those We Love Alive is a work of interactive fiction published by Porpentine. You can read the work online.
One of the unique features of the work is it asks the reader to draw sigils on their arm at very moments during the story. Here is one example of such an instruction:
Draw a sigil of new beginnings on your skin.
The fact that these sigils are drawn on the skin seems significant. It means that the sigil is a part of the reader's body, rather than something like a paper that can be disposed of. This seems to be recognized by various other people who read the story:
When playing this I didn’t want to draw on myself, so I used a piece of paper. The symbols still meant something to me (and I still have the piece of paper), but I think some of the effect was lost.
Why exactly is it important to draw these sigils on the reader's skin, rather than something like a piece of paper? What changes about the story if the sigils are not drawn on the readers arm?