Satrapi uses shading in very different ways on pages 140 and 200. On page 140, she uses it to set the tone of the page. This is important because this event is not one that should be easily skipped over. The solid black background of one panel allows the reader to feel the intensity of the situation. Without the dark panel, the scene would still have a sober feel, but it would have much less effect.
On page 200, Satrapi uses shading to either isolate characters or make them blend in. The only colors used in the entire book are black and white. This makes it difficult to differentiate characters with colors, so Satrapi does this by using the far ends of the black and white spectrum. Panel four shows how Marjane was having trouble differentiating her mother from the strangers by completely shading all the background characters black except for Marjane’s mother’s face. Whether this was due to the long time elapsed since they had last seen each other or due to the crowd is left to the reader.
In panel five, all of the background characters are left unshaded while Marjane’s mother is shaded. This makes Marjane’s mother stand out clearly. The audience can feel as Marjane would have upon recognizing her mom.
I must admit that panel eight confuses me. It is clear that Satrapi is being intentional with her shading throughout the page, but all characters in panel eight are shaded except for one seemingly unimportant man. It is unclear what Satrapi is trying to say by this or if it has any relevance at all.