Although you already have your answer i'd like to post anyway
The point is to kill two birds with one stone.
When i did the first part of the book i ignored him and did it from Kanji to keyword... Big mistake.
I was able to produce a keyword from seeing the kanji but i wasn't forced at all to produce a kanji from seeing a keyword (if that makes sense)
Basicly if you see the keyword and you write out the kanji, you are both training your ability to both recognise
and produce a kanji (From memory)
Whereas if you do it from kanji to keyword you only really train your ability to produce a near useless keyword from seeing a kanji already wirtten out for you (Thereby not making you remember a kanji from memory at all, since it's already sitting right in front of you)
Going from kanji to keyword is also useless because, why would you want to train yourself to produce keywords that you will just discard later on, they are after all only handles to remember kanji until you start memorizing readings etc.
And although a lot of keyword can give a loose idea of what a kanji
could mean, not all of them are accurate or even close, there's no point in giving yourself such a handicap like being able to produce an English keyword designed to use in Mnemonics.
And yes, you are supposed to look at the keyword and write out the kanji from memory then see if you were correct. (Or a at least that's how i've always done it)
Hope this helped, and i hope it made sense, because i had a bit of a hard time trying to explain
