Hello,
The question means that if someone was going to write about you with the available information, assuming they couldn't get that from you, they would look at what you left behind, like pictures, posts, writing, notebooks, etc. The aspects most emphasized would be the ones most known about you, or the most important (that they could find) about you. The "left out that you think is important" would be the things that they couldn't dig up, the things that you would only know