They both have a bit in common. They’re both communist Asian states that the US went to war with during the Cold War and did not win. But the messaging regarding the two states is a lot different. DPRK is treated like the worst dictatorship ever, that kills you and your family for even thinking that the Kims are less than gods, whilst also starving. But Vietnam, they say… nothing.
Why isn’t Vietnam demonized like DPRK?
The simple answer is because the ROK exists. DPRK gets demonized as an example of socialism while the ROK gets praised as an example of capitalism. You see a similar dynamic with China vs Taiwan/Hong Kong/Singapore.