Reason for rejecting my works for quality

Thank you. I got answers to my questions.

If I were you, I would submit vector artwork as native Adobe Illustrator (.ai, .svg or .eps) files. You'll get more interested buyers that way.

Vector graphics are resolution independent, which means customers can edit & rescale them to whatever size is required without any quality loss.  They can't do that with rasterized .jpeg or .png files.

Convert to JPEG.

PNG is for images with transparency.

Read your Stock User Guide.

• https://helpx.adobe.com/stock/contributor/help/reasons-for-content-rejection.html
• https://helpx.adobe.com/stock/contributor/help/quality-and-technical-issues.html
• https://helpx.adobe.com/stock/contributor/user-guide.html/stock/contributor/help/photography-illustrations.ug.html
• https://helpx.adobe.com/stock/how-to/tips-stock-image-acceptance.html
• https://helpx.adobe.com/stock/contributor/help/vector-requirements.html
• https://helpx.adobe.com/stock/contributor/help/generative-ai-content.html
• Model/Property Releases:
  https://helpx.adobe.com/stock/contributor/help/model-release.html
  https://helpx.adobe.com/stock/contributor/help/property-release.html
  
  

Drawing errors

I had to enlarge this a great deal to see it, but this one might be due to the haloing.

Can you explain what this is?

I have never seen a tripod head of this shape.