[Dirvish] Beginners questions

[Rémi Boulle]

Hello,

I am using dirvish to do a daily backup of my /home directory.

For what I understood dirvish write only the changed parts of the 
changed files.
My first image is roughly 5 Go, so why the second one is 5Go too ? (no 
files were changed)

Does it mean that all those images are "real" images ? eg I can delete 
last monday image without having any problems ?

Thanks.
Rémi.