It is explained below what does other snapchatters mean on Snapchat?

The manifestation “Other Snapchatters” refers to Snapchat users who have viewed your story but don’t pursue the app. While that answers one question, it puts forward several more. Does this mean that a buddy has unfollowed or blocked you? Let’s take a closer peek at who gets the “Other Snapchatters” title.

You Have Been Removed as a Friend

When someone you are friends with on Snapchat views your story, the platform will indicate their username under normal story viewers. This compromises if someone you thought you were friends with on the platform demonstrates up on your story outlook as “Other Snapchatters,” then you are no longer friends on Snapchat.

I hate to crack it on you, but your friend presumably unfollowed you and is now an “other.”