How to test Broken images/Thumbnails in a Native App?

I am automating an app where we show images/thumbnails of videos that are available to view (Similar to Netflix) and one of our crucial test is to verify that all of them are loading and visible to user.
I am kind of new to Appium, so bit confused about how to test it or if you can advise anything that we can add in the existing App code (Development side) to help in automating the scenario?
Thanks in Advance
Note: All the images share same class and ID (no text though)

You can use Appium to screenshot the device/simulator, or possibly get the images, but you’ll probably need some 3rd party software like to examine the screenshots or files.

The issue here is that the images/content is not predefined. It varries and thus it won’t be possible to compare a screenshot with somekind of source image. Correct me if I am wrong but I believe the image comparison tools compare images from pixel to pixel.
Moreover I just want to confirm if the image is available or not. Doesn’t matter what the image is.

Why would you not predefine test data? Are you doing QA work or not?

in our current dev setup, we do not have control on the algorithms (Client owns it) and the data they fetch is from Prod (I know it’s not a good practise but it is what it is right now)

Ok, does the app have a default image that it subs when the thumbnail is not available? You may be able to look for that…

This is a pretty tough problem though. I think you should try to create a broken image/thumbnail and examine it closely. Maybe there is something unique (like size) that would represent the broken image? Not seeing it first hand that’s my best guess.

Sadly it’s harder on native apps. On the web (desktop/mobile) side, you could use something like this, if not doing the full image pixel/byte comparison:

I don’t know of any equivalent on the native apps side. Perhaps if only Apple and Google/Android exposed a similar API we can query that would be nice…