Inmu memes might be a bit too niche to follow without context, but I'll try my best to explain this one...
So there's this scene in a gay pornography called "Naughty Workplace White Paper XIII" (職場淫猥白書XIII), in which a sushi delivery intern takes out an inarizushi from a customer's order and eats it, assuming it was included by mistake. The customer then finds out, threatens to call his boss, and eventually agrees to let it go on the condition that the intern come in to make inarizushi with him. The intern steps inside only to get knocked out by hypnotic gas, and... you can probably guess the rest.
The connection to Niko here is because inarizushi is essentially her character image, being her specialty dish that she often makes, serves to others or eats it herself. To make matters worse, there's even an in-game animation from the Lore Pursuit event where she sits down and eats inarizushi in her FOX EATS outfit. Hence the parody.