What are the actions that I can perform on those figures in a Figures List?

For original images, click the red status icon to send a request to the archive for the original image. After a request is sent, the status icon will change to yellow. Note: You can also initiate this action from the action menu by selecting "Request originals". From the action menu, you can apply this action to a single figure, all the figures in a chapter, or all the figures in the project. This action only applies to figures with a red status in a project.

For images selected from a book, the yellow status icon indicates that the archive image has been requested. See How do I request high resolution images from a Figures List?
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For images selected from a curated collection or journal, click the yellow status icon to download the high resolution version. After an image is downloaded, the status icon will change to green.

For images selected from a book, the green status icon indicates that the archive image has been received. No action required. The best version of the image is available. See How do I request high resolution images from a Figures List?
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For images selected from a curated collection or journal, the green status icon indicates that the high resolution version has been downloaded.
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For images from sources other than Image Finder, the green status icon indicates image has been uploaded from file by Contributor. See How do I add a figure from an image not found in Image Finder into a chapter in a Figures List?