These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Nightmare Fuel: Martha's nightmare in "Too Much Martha" portrays her as being literally paper thin and unable to really move on her own, yet still forced on a (stricter) diet by Helen to "lose weight". While the sequence has some admittedly amusing moments, such as paper-thin Martha being flown like a kite for a "walk", Martha's panicky And I Must Scream state and Helen's obliviousness (or indifference) to Martha's condition make it all the creepier.
Periphery Demographic: A sizable portion of teens and adults enjoy it for how surprisingly clever the writing is.
Squick: Martha eating and rolling around in garbage. Also, in one episode she claimed to be rolling around in dead snakes.
The Woobie: Some episodes depict Martha in this fashion, such as when she believed she'd been cursed with bad luck, leading her to run away from home. Sure, otherwise she's happy in most episodes, but when she's suffering, she does so beautifully!