Apply minor edits to text in 04

Author: vyasr

episodes/04-changes.md

@@ -342,12 +342,12 @@ but not yet committed.
 > makes a permanent record of it (as a commit).
 > If you don't have anything staged when you type `git commit`,
 > Git will prompt you to use `git commit -a` or `git commit --all`,
-> which is kind of like gathering *everyone* for the picture!
+> which is kind of like gathering *everyone* to take a group photo!
 > However, it's almost always better to
 > explicitly add things to the staging area, because you might
-> commit changes you forgot you made. (Going back to snapshots,
-> you might get the extra with incomplete makeup walking on
-> the stage for the snapshot because you used `-a`!)
+> commit changes you forgot you made. (Going back to the group photo simile,
+> you might get an extra with incomplete makeup walking on
+> the stage for the picture because you used `-a`!)
 > Try to stage things manually,
 > or you might find yourself searching for "git undo commit" more
 > than you would like!