Because they have near identical scores
You're voting for final placements in the overall results. Either Carmella will be in a higher position, or Yulia will. As of right now their scores are within 0.1 of each other so it kinda shows that they're pretty much equally liked by our regular voters. Tabbers and Scheglova were also very very close in scores and thus they were paired together. Scheglova won, so she'll place 1 spot higher then Tabbers
Example: (Spoiler)
So these two will battle it out to see who gets top billing over the other.
You're going to see a lot of models who are paired that you either love, or hate equality.