Please visit this product page https://www.lackofcolor.com.au/collections/straw/products/island-palma-boater?variant=31688654454854 and press add to cart, you will notice a call-out or container that offering another product. What is this app?
Ash here from the Shopify team.
Based on what I can see on the public facing product page, it appears that that would likely be some sort of product upsell application. With that being said, without taking a closer look into the back-end of the store, it would be hard to say exactly what app that is, or if it is indeed being generated by an app even.
Is this your own store? If so I would be happy to move our conversation to email so that we can authenticate you on the store and take a closer look together. Alternatively, if you could take a screenshot showing the apps you have installed, I may be able to identify it from the list of apps on your shop.
If this isn't your shop, but you're looking for a similar app to use in your own shop, there are some great product upsell apps you can check out right here in our Shopify App Store. I hope this information is helpful, and I look forward to seeing your reply!