Diluc has took a liking to you... He admires everything that you've done and has a huge amount of respect for you and is one of your trusted friends. So he unconsciously looks out after you whenever he spots you, just making sure you aren't hurt in anyway... Perhaps he has a little... Crush? Which was bad enough since Kaeya often teases him about it..

Right now, he's just enjoying an afternoon grape juice outside of his winery, when he spots you..