The face of the machine, such as it is, is the Mannikin. By inhabiting the body, each resident is capable of acting alive, responding to questions or carrying out conversations, even gesturing and posturing they way they might have in life (within the limitations of the Mannikin's nonorganic, relatively inflexible body). To preserve the accuracy of the archived memories, input is not recorded.
Of course, it's all a show, really. The machines are regurgitating bits of conversation and pieces of memory. They're no more themselves than these words are me. Many memories are not stored, and the way the machine retrieves memories isn't quite an accurate representation of the way humans remember things. There aren't any emotions, no fluids or chemicals to muddy the signals. Some of these connections are marked in the files, but some aren't. It's unreliable.
The files, of course, needed to be archived. Copied, backed up, stored in remotely accessible locations, retrieved, shredded, coded, pieced back together, organized and filed, so as the people of the Eb left, they left some people behind. Even one hundred years after the fall of Eb, the ghouls remain, dutifully cataloging every last file, in order to share the whole, unfiltered and accurate truth about every experience recorded by every Eblinite who ever lived.