Why are some sunglasses shown on the top page of Google?
What you can tell
First of all, your site needs to run as fast as it can, to guarantee a comfortable exploring experience when some people look around in your online shop, which is why the Google PageSpeed Insights is there, checking your site's loading speed of both computer and mobile phone versions when someone clicks on your page.
You may think that if your site has a quick loading velocity, one of your pages shall be shown on the first few pages at Google. Unfortunately, things don't always happen as you expected. Some products lie there while they have a poor loading tempo and some pages are even lost.
So here is the second factor, that your page needs to have enough content for people to read, including fresh pictures and vivid texts, and descriptions matter much more than photos.
However, you'll find although some pages have a quite few words in a page, they repeat themselves in many other pages at the same site. For example, they keep saying 'About Us' in every page, which is quite a nonsense when you explore the second page at the same site, shown as below:
Inspirations Gifts and Goodies was formed in 2009 with the purpose of "INSPIRING THE GIFT OF GRACE". We looked to do this by inspiring positivity and confidence in one's self. We offer items that have an inspiring Christian message and is specifically tailored to your desires of positive expression of the love of Christ. In addition we offer excellent gifts for that special someone that might be on your gift list. We are dedicated to carrying high quality, unique items in our online store to create a unique shopping experience that will make you look and feel fabulous about yourself and others. Our product selection is quite extensive and you are sure to find something to meet your discerning tastes! Our friendly, fashion-forward staff is here to help you find exactly what you are looking for.
We are a family-run business, that take pride in our customer service. We purchase most of our products from local designers. Browse through the gallery showcasing some of the many products we carry. We promise you that you will find great items at affordable prices. Thank you for visiting our online store.
Or you may keep finding some reminder or warning thing on almost every page as the following:
WARNING: these novelty “funglasses” are sold as an accessory for entertainment or costume use by adults only. May obscure vision. Not for children under 18. Not designed to provide medical benefit or to any type of personal protection, including protection from impact or UV rays. Do not use while driving or at night. Do not use with prescription lenses. Please keep this advisory so you can refer to it in the future.
I don't think i have enough patience to read them all in the first page, not to mention how i'm dull when i find the same thing in the second page.
What you can't directly tell
Apart from content, Googles also pay its attentions to how often a site is visited. That a site, such as Amazon or eBay, is frequently called on normally means it is popular among people. But you don't always find a pleasant shopping experience at those sites, because lots of pages repeate something common again. For instance, most of spectacles may show specification as below:
Item specifics
When I keep finding these boring texts on most pages, I don't feel like going any further and caring how many other people are visiting them at the same time.
And there is another cause that influences how Google thinks a site matters. If a number of other sites are connected to a specific site, it means that the site is appealing to many people who like to introduce it to their friends at places where they often hang out, like Facebook, Twitter, Instagram, TikTok, etc. It works like a reference letter, which proves you're good at something and that you're okay to count on.
However, if this way works, then it shall be munipulated too. It is easy for people to buy links or make links themselves to direct people back to their sites; the reference means almost nothing then, because you find it hard to tell if a site is referred to by real consumers who are interested or by others who are simply owners of some sites.
Conclusion
I know that Google has a more complicated algorithm which they keep improving and will never reveal, or many people will try to maneuver it as soon as they can. However, the above 4 factors will never lose their positions when Google determines if a site is well organized. At least until now, i don't think Google always make a reasonable rank when those elements shall count.