Flash swf export and image compression

I'm not sure if this is intended behaviour in DP7 but I've noticed that if you have a photo, say 1mb, and you put it in a flash file and resize it only slightly smaller by a couple of pixels it exports to a very small swf that's <100kb. Which is great. But if you keep the image original size on the page or resize it bigger it doesn't seem to compress the image on export and the swf ends up over 1mb.

I had 4 reasonably sized photos in a flash file and it was exporting an swf over 5mb, but when I figured out what was going on (I made sure all uses of the images were smaller than the original) it was possible to export an swf less than 1mb.

Anyway not sure if it's intended but this might be useful to anyone who runs into a similar file size problem.

Just a quick follow up, I opened the exported file with a swf decompiler and the photos were being stored in the swf as large 2mb+ bitmap files instead of jpegs. I'd have thought it would export them as jpeg no matter what the size on the page, especially if they are large photos.