Meaningless
When King Arthur saw Leonel walk in, he of course felt a complex swirl of emotions. For better or worse, he felt an even more visceral reaction than when he saw his daughter. But, maybe that made sense. After all, Arthur had clashed with Mordred many times before, it wasn't as though this was the first time he was laying eyes on his daughter in years.
In comparison, Leonel was like a beacon that awakened him in many ways. Of course, that was most exacerbated by the death of six of his brothers, but Arthur still felt that the initial catalyst was Leonel himself.
However, what Arthur hadn't expected was for Leonel to suddenly erupt with such killing intent the moment he stepped into the Royal Court.