Creepy, crawly President Snow is always a bearer of bad news. His presence casts an evil shadow over much of the first half of Catching Fire. Katniss is always looking over her shoulder and wondering what kind of punishments he might be devising for her. And she's right to be worried. After she fails to convince him of her love for Peeta, he dumps her right back into the Hunger Games arena.
Snow is ugly and gross, and he reminds Katniss of a snake. She describes him as having a very particular smell when she approaches him in person:
The smell of roses and blood has grown stronger now that only a desk separates us. There's a rose in President Snow's lapel, which at least suggests a source of the flower perfume, but it must be genetically enhanced, because no real rose reeks like that. As for the blood… I don't know. (2.16)
What else is there to say but "yuck"? Blood and roses sounds about as bad as a Lady Gaga perfume. In Snow's case the smell is usually accompanied by the delivery of bad news. Here he's telling Katniss that he knows about her dark secrets and that she can't fool him. Snow makes it sound like his eyes are everywhere and he knows everything. Compared to the other citizens of Panem, he certainly has a great deal of power.