How to view photos in Dropbox that were saved as zip files

There doesn't seem to be a way to do this at the time. Using Windows shortcuts is one possibility to make it as though the files are located in the same folders, however, it seems like it would get a bit complicated if there are a lot of folders.

There is a feature request for this exact issue, which you can vote on.

Other features you may want to look for is the ability to watch any folder, which you might be able to use in conjunction with your file system to create a limited set of folders to sync. Another one that might help is excluding certain file extensions, this would help if all the large files are of the same type (e.g. .exe, .avi, etc.).

You could try this method posted on Mac OS X Hints:

Just stick the folder of files into your public folder, and head to the Dropbox webapp. Click on the folder you want to share, then click the “Get Link” button at the top of the page. Add ?dl=1 to the end of it, and send that link to your friends. It’ll zip the file up for them and download it to their computer. (Lifehacker synopsis)