They rejected my images made with artificial intelligence of ecological themes.

They fulfill the commercial function and in terms of quality it is not inferior to other images that have been approved for me.

  

By @thisisepiko

Let me put it like this: if you have the same errors in your accepted assets than you have in these, they were wrongfully accepted. That is a real problem as the stock database is flooded with bad assets because some moderators do not or cannot do their job correctly. 

For the whale: you have visible compression artefacts all around the picture, especially in the white lines. 

In the background texture you also have occasionally "dust" particles that could be cleaned up. Generally speaking the asset would have more value for the buyer, if it would be a PNG file fith a transparent background. 

The thermometer has about the same issues:

In addition you have rendering errors in both assets.

The assets as such are OK with some commercial value, but the issues in the files do make them unusable for most applications. 

What I would do: I would add transparency to the background, correct the compression artefacts and rendering errors, make them smaller (that will make disapear the rest of the errors) and group them together in one or two files. That will create nice environmental icons. You won't make that much, as a buyer would need only to licence one or two images for getting an icon collection of the same style, but as the assets would be much more useful, I think that you could offset that with a good number of sales. 

Personally, I would probably have done this in Photoshop or even Illustrator. It would have taken more time to create, but it would be error free and much easier to cut out. And as soon as you have create the necessary custom brushes, you could expand the collection easily.