"Law of attraction" is, by its meaning, total Dhamma and all works on that. It's the "law of attraction" that keeps one in the wheel, and that of escape, with faith into liberation as alternative attraction. For one once attrated by what is worthy to give in, one has already designed ones deliverance.
Without such as right imaging not much success, yes. Where ever one feels attracted to, what ever one nurishes, to that one falls and vici-versa.
Those who have confidence in the quality of dispassion have confidence in what is supreme; and for those with confidence in the supreme, supreme is the result.
That's most importand, and yes. The related emotion is called pasada and pushed by samvega.
Yet one has no pure imagination of full awakening since there is no reference experiance. But once faced only a little of liberation, once a base for imagination has been seen, there is no way back. So it's not wrong to say: "one who has a (real) imagination of liberation, is as good as already delivered there".
Now it requires a path to be developed to see the quality for one self, starting with right view, goodwill for all beings, right conduct, effort...
The first step is to purify ones image of perfect virtue, after refuge into the three main imaginations, Buddha, Dhamma, Sangha, all to lift ones qualities and gain better imagination of a healthy being:
The usual nimitta, better kammaṭṭhāna is "the Buddha", as object of perfect release, the first Meditation object. It starts all with this imagination: Buddhanussati, followed by the next anussatis, attractive reflection objects.
Once a certain stage was once reached, one can go on with a more pure object of attraction, on vimutti by non-craving, liberation, it self. upasamanussati
"Among whatever qualities there may be, fabricated or unfabricated, the quality of dispassion — the subduing of intoxication, the elimination of thirst, the uprooting of attachment, the breaking of the round, the destruction of craving, dispassion, cessation, the realization of Unbinding — is considered supreme. Those who have confidence in the quality of dispassion have confidence in what is supreme; and for those with confidence in the supreme, supreme is the result.
So the beginning imaginations are:
Buddhānussati, dhammanussati, sanghanussati, silanussati (ones virtue), caganussati (ones generosity), devatanussati (qualities equal the Gods).
Details are found following the links.
(Note: not given for trade, exchanges, stacks or other bindings but for freedom from entertaining)