I suspect this is a sponsorship deal. She's never mentioned these things before, but all of a sudden she's mooing about how they're her favorite and she just can't get enough, and how she had to buy an awesome size 3X shirt to commemorate her love for them.
So yeah, I think she's getting paid to do this, because god damn, Little Debbie knows their audience.
Just watch a deathfat eat. They shove in huge mouthfuls, barely chew them before swallowing, and go straight into the next bite.
There's a lot of shitty processed food that tastes good when you first put it in your mouth, but the more you chew it, the more aware you become of unpleasant textures (that Crisco/shortening texture you describe is one) and flavors that emerge from behind the initial blast of sugar, salt, and/or spices. Corn syrup has a telltale flavor that makes me think of sulfur, and cheap bakery items and snack cakes usually have weird metallic and bitter tastes that become noticeable if you actually bother to chew them.
Tess barely chews any of this shit. She doesn't linger over it, savoring it, because if she did she'd just get grossed out and never want to eat it again. Nah; she just shoves it into her gaping cakehole at top speed, and swallows each massive mouthful before it has any chance to reveal how shitty and gross and low-quality it is.