In most browsers the shorter and more specific variant of the code will run faster (in some instances much faster) than the second variant and so it makes sense to use the shorter and more specific version. It also makes the code easier to read and maintain.
In the United States and Canada frozen ice on a stick is generically referred to as a popsicle due to the early popularity of the Popsicle brand, and the word has become a genericized trademark to mean any ice pop or freezer pop, regardless of brand or format.
The sparkling part is carbon dioxide. If it's just sparkling water, then no it's not pop. It's just fizzy water. If it has added sugar or artificial sweeteners and flavourings then it would be similar to pop. I suppose it depends what aspect of pop you're trying to give up - sugar, artificial additives or bubbles.