JPG is a compressed format. Perhaps you are confusing the file size on the disk of a JPG image ( 2 MB ) with the actual memory size of the image once it is "uncompressed" into Elements . The actual size of an RGB image in Elements is the product of the pixel dimensions ( 3719 x 3688, for example ) , times 3 ( for 3 bytes, 8 bits of data for Red, Green, And Blue ) . My image is 39.2 MB, but would be different sizes saved on the disk drive, depending upon which compression options I selected for my JPG save .
Hope this helps