If your modifications to the images on your Amazon listing are not appearing even after 24 hours, there could be several reasons for this delay. Here are some steps you can take to address the issue and optimize your listing page:

1. **Clear Cache and Refresh:** Sometimes, changes might not immediately reflect due to browser cache. Clear your browser cache and refresh the page to see if the updated images appear.

2. **Check Upload Status:** Make sure that the image modifications were successfully uploaded and saved on the Amazon Seller Central platform. Double-check the upload process to ensure there were no errors.

3. **Contact Amazon Support:** If the issue persists, reach out to Amazon's seller support for assistance. Explain the situation and the specific problem you're facing. They might be able to provide insights into any technical issues or delays.

4. **Image Guidelines:** Ensure that your modified images adhere to Amazon's image guidelines. Images must meet specific requirements in terms of size, format, quality, and content. Violating these guidelines might cause your modifications to be rejected.

5. **Product Page Moderation:** Amazon's product pages go through a moderation process. It's possible that your modifications are being reviewed before they are published. This process can take some time, so be patient.

6. **Wait for Resolution:** Sometimes, technical glitches or delays might occur on Amazon's side. If your changes are valid and adhere to their guidelines, the issue should be resolved over time.

7. **Alternate Formats:** Consider uploading the modified images in different formats to see if they appear. Sometimes, using a different format might help bypass any technical issues.

8. **Document Changes:** Keep a record of the modifications you attempted, including dates and details. This documentation can be useful if you need to escalate the issue with Amazon's support team.

Remember that Amazon's platform can sometimes experience technical issues, and delays might occur. If you're not able to resolve the issue through the steps above, your best course of action is to contact Amazon seller support for direct assistance in getting your modifications applied to your listing.