How does Scrivener treat image size when compiling to mobi?

Does Scrivener change the filesize of images (in kb/mb) when compiling?

I’ve imported a few dozen images into my images folder, all at 2200 x 2600 pixels, and about 1mb each in size. In the draft document I resize these to approx 600 x 700 but when I come to compile to a mobi file for Kindle Store, are these files automatically reduced in size or will they still be about 1mb each?