From memory, the fake (right-handed) Infinity Gauntlet existed before Thanos made Etri create the left-handed version that he used with the real Infinity Stones.
This gauntlet is obviously sized for Titans, but who was it made for, and why?
This Gauntlet was nothing more then a fake. In Ragnarok, we see a model/sculpture of the gauntlet in at the Etri's smith. The gauntlet most likely needed a certain size to properly have the right specifications to withstand the power of the infinity stones. Which explains the size. The gauntlet was simply there as a trophy for Odin and to make everyone believe the gauntlet was in safe hands to prevent fear amongst the asgaurdians.