If summoning a balor into the midst of a group of drow won't break invisibility (the spell specifically says you can summon monsters, remember)... I would say that throwing a light pellet wouldn't either. Later in the spell, it says "causing harm indirectly is not an attack."
The result of throwing a light bomb affects the drow, certainly, but it's not a specific attack on the drow. And this way, we don't have different results if the character throws a light pellet at creatures without light sensitivity.
The rogue wouldn't become visble, therefore, by throwing the daylight pellet. But they'd certainly know SOMEONE was nearby messing with them!