The eternal rivalry between physics and chemistry captured in perfect parental favoritism! Despite claiming to love both sciences equally, science (the mother) can't help but favor physics. That smug little physics face in the final panel says it all.
This hits differently if you've ever been in a university science department where physics often gets the funding glory while chemistry sits in the corner with outdated equipment. The "by a lot" part is just brutal honesty that would make even Schrödinger's cat both laugh and cry simultaneously.