I think the small load is due to it being almost 5:30pm there right now, the ship is about 1 1/2 hour away from the port currently and they want to get back out to sea before dusk. So there is probably only enough time to take (load) the 60 or so people they have waiting. These also may be special needs people.
I doubt it's only because of losing daylight. They've been talking about 60 passengers for hours. Besides they hadn't planned on being slowed down by the Israel blockade nor did they know if they'd be given free passage at this time. Seems more than likely they already had a list of "special" passengers. But who knows since none of us know what's really going on behind the scenes.