The modern blue whale is longer in body length, but only a fraction as heavy as this newly discovered whale.
The modern day manatee, or sea cow, superficially resembles a walrus without tusks(though much bigger even than a walrus), but unlike walruses and seals, it cant come on land- its limbs are not built right for that- so it stays in the water all of its life. Walrus breed on land.
This whale may have had a manatee type lifestyle and grazed on sea plants instead of chasing fish, or even chasing plankton. So it might have been to other whales what manatee are to seals...a big sedentary fat ass! Lol!