It was a joke. People were complaining that Todd worked for BP- I think the divorce rumors were being spread at the same time. The reply from the aide was “VERY funny”.
Besides this was 2007- baby Trig came along 2008 :). Obviously the humor went over the libs heads.
emails about Todd & the double standard
http://s3.documentcloud.org/documents/307082/pra-gsp02-0006313.pdf