Have you ever been to a greenhouse? Have you ever grown food?
This is not what watering looks like.
This is clearly a foliar spray, which could very well be certified-organic neem oil, or something like a foliar fertiliser. You would never carry around a small tank like that for watering in a production greenhouse. Many of these things are safe and water-soluble (ie. not bioaccumulative), but have a negative health impact when aerosolised, so the worker has to be protected during spraying.
There are plethora real, pressing sociopolitical issues going on here with GMOs in terms of patenting biological life, and encouraging unsustainable monocultures, but it’s so myopic and navel-gazing to make it all about the totally unfounded claims of health impacts on the consumer side (by the way, consumer demand is why GMOs exist in the first place)!