Save as jpeg produces variable widths?

Hello;

       I'm creating jpegs, & then pulling them into NX, so I can create cgm files for a customer. My question is why is SW creating different exported image information widths, for the same 11 x 17 B size drawings? The customer is creating drawings & I'd like to give them consistent cgms.This is all just accepting the defaults for the b-landscape paper size. Why is it changing it? The height stays the same?

Thanks in advance for any input.

Rob_D SW_2019 sp5.

SolidworksImport/export