This means light from very far away has to struggle to overcome that expansion to get to us, which means the light loses energy (like you have to use energy to pedal a bicycle up a hill).
(This; means; light) (you; to use; energy; to pedal a bicycle up a hill) Context(you to use,List([134, 149))):(you; to use energy to pedal; a bicycle; up a hill)
you to use,List([134, 149))
This you you
means to use to use energy to pedal
light
energy to pedal a bicycle up a hill
a bicycle up a hill