There could be two different situations when you might not see the images: when the image is embedded but not downloaded or when the image is remote, and only linked.
Both have the corresponding options controlling this behavior.
In the first case, the rationale is to save mobile data, and you can choose to load the rest of the message, including the images.
In the second case, the rationale is your privacy. One modality of verifying that you received their message that is used by spammers and legitimate marketers is to link a remote image with a unique name. So, on the server side they can track which file name was used, uniquely identifying the recipient e-mail address.
Occasionally, a similar behavior can happen when the sender links an image using a local link pointing to his/her local hard drive. Then, obviously, that image is not available...
What is the note/message shown by Aquamail when the image is not displayed in your case?
If you can post a screenshot (or send it to support / at sign / aqua-mail / dot com ), it would be easier to help you with your situation.
