What determines the rating given for a player PER GAME?

Hello,
I am curious about lichess rating system.
I have already read the the part "What rating system does Lichess use?" in Lichess FAQ but it doesnt really answer my question.
Well, I do not understand what determines the rating of a specific game.
For example, winning a game mostly gives me 5-7 points, but sometimes its 8 or higher, and sometimes it's 3 or 4.
So, what affects the points given after a win? Is it the average centipawn loss? or am I missing something, and actually somehow it's only up to the the result and to the confidence interval mentioned in the FAQ...

Thank you

Lichess use the Glicko rating sytem there is the wikipeada page if you want
en.wikipedia.org/wiki/Glicko_rating_system

Short answer: If you beat a player much higher-rated than you, you gain more points than if you beat someone rated closely to you. Conversely, if you lose to a player much lower-rated than you, you lose more points than if you lost to someone rated closely to you.

" Is it the average centipawn loss?"

No, the actual game play is not considered, only the result (0:1, 1:0, 1/2:1/2) goes into the rating calculation.
As mentioned above, the reason why you get awarded a different number of points depends mostly on the rating difference between you and your opponent. In addition, there's a parameter called "rating deviation", which basically means that you earn or loose more points if your rating is unstable (for example, because you have not played so many games yet). - that's why sometimes an equally -rated opponent gains or looses many more points than you.