Here is the manual for the software if anyone is interested. It might be useful for answering some questions.
End-user documentation for XenForo
xenforo.com
Here it explains what a reaction score is:
xenforo.com
"
Reactions
Reactions allow users to express the emotion they feel towards a piece of content with a simple click. The most basic reaction is
Like, with which everyone who has not been living in a cave for the past decade or so is familiar.
XenForo allows multiple reactions to be defined, such as
love,
sad and
wow, each of which may be defined to be a
positive,
negative or
neutral reaction.
Each reaction type may be assigned a
reaction score. For example,
Like is given a score of (positive) +1. If ten users 'like' a post, in the absence of any other reactions, its reaction score will be 10. Reactions may also be assigned neutral (+0), negative (-1) or custom scores depending upon their use case."