Players are strongly encouraged to attend both sessions. Coaches usually plan different activities so they can see different things on each day, so participants aren’t just doing the same thing at both sessions.
That said, life happens, so if your player can only attend one session and wants a chance at a Lake Hills team, we definitely want them to come to at least one session.
It would be a good idea to reach out to the coach and notify them in advance so the evaluators know they need to pay close attention and get a good look during the one session they do attend. At the very least, if the player is only coming to the first one, let the coach know when you arrive.