Yea size and weight. I didn’t see an issue with the description.Not really a contradictory.
adjective
massive (adjective)
- large and heavy or solid:
"a massive rampart of stone"- exceptionally large:
"massive crowds are expected"
- very intense or severe:
"a massive heart attack"- informal
particularly successful or influential:
"the title song became a massive hit"- geology
(of rocks or beds) having no discernible form or structure:
"a massive limestone without bedding planes"
- (of a mineral) not visibly crystalline:
"massive sulfides"
E.g. A massive empty cardboard box (the size of a house) would be lightweight compared to a brick house.