Adobe Lightroom + Photoshop Express / iPad Image quality/Size Issues

Hi all,

PLEASEEEEE help this is driving me made. 

So very basically, if I edit a photo in Lightroom using my Ipad then export to camera roll the file ends up about 2mb in size. If I do the exact same process on Lightroom on my Mcbook and export to the desktop or wherever the file size is far bigger 10mb + ?

Im assuming their must be a setting somewhere in the ipad> The only ones ive found say its being "exported at 100%"

Kind Regards

Paul