Now this is interesting and more relevant to the op's original complaint instead of the sideways off the point rants from some others, thanks for finding and posting this.
As others have said, yes, the pop bottle design is a terrible idea, I don't think any responsible parent would think otherwise.
As said though, looking at the design, this appears to be a rip off of the original fantasi design, the logos aren't nearly the same and looking at them as a premium and expensive ejuice manufacturer they're unlikely to provide diy kits.
This just brings to light that facts should be garnered before a witch hunt commences with people ranting at a manufacturer unnecessarily. Like an angry mob storming the gates of Chanel because a knock off perfume from a Spanish market gave aunty Ethel a rash.
The fact you had to Google diy kit shows also it's a specialised thing which means the responsibility to keep it away from kids would be down to the purchaser, which again comes down to responsible patenting and adulting instead of expecting the rest of the world to do it, my parents made sure I didn't eat washing powder etc as a child despite those being in pretty coloured boxes.
A child is not going to Google diy vape juice, pay that price, mix it and drink it but that doesn't alter the fact the packaging shouldn't be for sale.