Not trying to be condescending but, Not all tank car commodities have to be placarded. Many commodities are classed N9 which are non-placarded cars (loaded or MT) with a placement restriction not to be placed next to a shift-able load. Looking at the spring packs of both these cars they appear to be loaded to me. Tank cars that require placards have to have them displayed for loads or residue last contained. Cars not displaying proper placards (missing on ends or sides) are not to be picked up en-route (FRA Hasmat). The car placarded 2078 has placement restrictions, but I dont have the charts in front of me to see what they are. There is a bunch more and others may want to elaborate more but you get the general idea.