Yup. Exactly my thought. Oh and if you get one of these, it makes pouring even easier.
The "Buy Box" is the box on the product page. It's what most Buyers see and they generally just push the button. But usually there are other sellers. If you look at this page, as an example, you will see the sort of page you will probably be relegated to as a new seller.
https://smile.amazon.com/gp/offer-listing/B00NNM05HA/ref=dp_olp_new_mbc?ie=UTF8&condition=new
That said, sometimes other sellers are shown below the buybox. Here's an example of that.
https://smile.amazon.com/OXO-Good-Grips-Batter-Bowl/dp/B001CDP5VS?ie=UTF8&ref_=cm_cr-mr-title
I don't know how Amazon makes the decision to implement one format versus the other. You might see how the items you will be listing are shown to an idea.