Hi Benjamin,
A sign that a girl friendzoned you in Snapchat is when she never sends you private messages.
Just about every message that she sends to you is one that she has sent to the rest of her friends.
Another sign that a girl friendzoned you in Snapchat is when her messages tend to be relatively short and she rarely uses expressive icons.
When she does use expressive icons, she may keep them very generic in nature.
A sign that a girl likes you in Snapchat is when she sends you a lot of private messages that only the both of you can see and in those private messages, she tends to flirt with you.
Another sign that a girl likes you in Snapchat is when she is constantly watching your Snapchat stories.
This is especially true when she is watching your Snapchat stories at late hours when she should be sleeping.
Instead of sleeping, she is up watching your stories.
If she were then to like or comment on those Snapchat stories, she would be demonstrating that much more that she likes you.