Yes, eye contact breaks the no contact rule.
Remember, the idea is to give your crush the impression that you have completely forgotten about them and no longer care. As far as you’re concerned, they don’t even exist.
If she sends you a snap, you should not open it.
By not opening it, you will make her start wondering why you are seemingly ignoring her.
These are the kinds of thoughts that may start making her worry about her relationship status with you.
If you are able to also show that you are building new relationships with, preferably, other girls, through your social media posts, this also could help tremendously in making her feel a sense of competition and stakes.
Seeing this alone on your social media posts could be what makes her decide to unfriendzone you out of fear that she’s about to lose your attention and adoration.