My guess is that the the pitcher is the real deal. According to Google, the railroad and warehouse commission was tasked with regulating railroads, safety, quality of goods, and other duties as directed.
I think some official from the era took an ordinary pitcher and turned it into official quasi-government kit by affixing that seal to it. I don't believe it was intended for drinking but rather for checking the quality/quantity of something. I agree that the pitcher holds considerably more than one pint so it was likely used in conjunction with other equipment.
The seal is affixed in such a way as to be visible to a right-handed user. It is brazed on in a manner similar to how the pitcher is constructed. I also see "0" and "3" stamped into the seal. I imagine that the seal was intended like the inventory control bar code tags of today and was affixed to various equipment. The "3" appears to match the size and font of the other imprints. The "0" looks smaller. Also, the "0" and "3" are not stamped in the top corner, where there is space, but rather in the middle. This suggests to me that those characters were added by a different individual at a different time.
