I can google this issues til the cows come home. It is a a very old issues with no clear cut solutions. One that shopify blames google for. Shopify states in past threads that they fixed the issue. I can assure you that they did not.
Solutions (that i can't implement)
Shopify is always a huge pain to work with as a professional developer. Shopify is suppose to be top notch for SEO but they can't even get this right.
Here is an example with my site:search. Curiously there are 12 images. However, there should be 30k+ of images. So I am curious why I have 12 images but none of the others from the sitemap.
Not saying this may not be an issue, but over half my images are showing as indexed and I get more traffic off google images than I get from anything else...
But if you want to talk issues, lately (I think since they implimented the new Dashboard) Shopify's stats are telling me I'm getting lot more site visits than my unfiltered Google Analytics profile is reporting... So in the long run who knows, the longer you do this the quicker you'll realize a lot of these reports and stats are not correct. The real key is, if you aren't seeing large drops in traffic I probably wouldn't worry about it. The Google Search Console is a little unreliable too, I frequently have to resubmit the sitemap to get the graphs to show as pictured above. I'd be more concerned if your pages weren't indexing under the Google Index - Index Status page, I've found that's more reliable than the sitemap indexing info. I've had the graph above show no photos as indexed yet I saw no drop in traffic or impressions on Google Images. I've also had the Sitemap Index graph suddenly go right to zero on everything (including webpages) and saw no major change in traffic, so I don't know how reliable that information really is.
Also if you have 30,000 images I'd be looking at both how you're naming them and if you're taking advantage of the Alt Tags and what size images your using (remember Shopify scales images down so you can upload larger sized images), all that comes into play with Google. We spend a lot of time on our images to get the best SEO and we don't have anywhere close to that many.
Thanks for replying. I believe if you are seeing a change in index images but not on page veiws then it may mean that the previously indexed images are still present in google search results.
As far as my images go, they are both named and alt taged properly. Every single image is processed with proper keyword names for their relevant product.
I have 30k images but google image search returns 14 results today site:piratemx.com
There is no clear cut solutions to this issue anywhere or any way to debug it.
edit: Your image did not display.
Maybe you can see the image now...
I wouldn't be so quick to blame Shopify. Just a comparison of what we get. Via webmaster tools in the last 30 days we've had about 11,000 impressions on webpage search results, on images its almost 300,000!!!
I looked at your website, if you want my honest opinon it is not very SEO friendly. I had to click through 5 pages before I could acess a product page, and then your product pages have very little written descriptions or information. The information you do have seems to be the same phrasing and info with just a word or two different on each page. SEO is a fine art, I don't claim to be an expert, but having a vast catalog of pictures alone is not going to get you there. Google is not picking up those pictures because of the lack of written unique content and that fact it's not assigning high priority to your product listings because they are too deep into your website.
It should take about half as many clicks (or less) to get to a product page. When Google crawls a website they want to see high quality content within a click or two off the main page. Your product descriptions should be unique and detailed with applicable keywords. Creating blog posts help trememdously to get Google to see that your website has high quality content. But I'm pretty sure your issue is neither Google or Shopify's fault. I think reading some articles on good website SEO practices would help tremedously.
While not a direct solution, I did want to let you know. As of today, June 21st, 2021, we have launched the ability to edit the robot.txt file to give merchants more control over the information that is crawled by search engines. You can learn more about how to edit your robot.txt file through our community post here.
Due to the age of the topic, I will be locking this thread. If you have any questions about the new feature, please do not hesitate to create a new post under our "Techincal QA" board.