What it adds is the fact that she thinks that she's doing more than she actually does because she brings the same character defects that ruin her as a housewife to the table when she goes out into the world. Bear with me as I list said flaws:
- Poor Time Management Skills: From what I've seen of Elly when we actually do see her at work, it's sort of obvious that the same sort of disorganized behaviour that makes her into a catastrophically inefficient tornado of failure at home causes her to horrifically over-complicate a simple procedure and turn it into an exhausting struggle against her own cluelessness.
- Lack Of Focus: It's not much of a surprise that Elly has the same angry scowl using office equipment that she does when she's manning a sewing machine because both phenomena require something she lacks: the patience and clarity of mind to deal with exacting procedures.
- Poor People Skills: As her biting into a phone book because she didn't get the fawning praise she wanted reminds us, we're dealing with the same tetchy, easily angered and sort of clueless hot mess when she's behind a counter as she is when she's cooking Cheapie Weenie Casserole.
- Brittleness: Lynn's comment on how she took something that wasn't actually personal personally and was right to do so not only explains why it is that Elly can't handle any sort of disagreement at home, it also explains why any sort of perceived slight is punishable by the sort of huffiness we saw when John was wrong for not slowing work down to stroke her stupid ego.
- Hunger For Praise: Most of the reason why Elly's a poor fit for the domestic life is that she seems to need a ticker-tape parade for every little thing; this makes her a poor employee and worse boss because she's a shining mark for any huckster who can butter her up.
- Imperfect Knowledge Of Her Surroundings: Her being fired from the library tells us all we need to know about her, I should think. We and Connie knew that she was the tent-pole character in an arc about the human cost of government cutbacks; she still thinks that she lost a popularity contest and that Sue and Monique are laughing at her behind her back because she's too stupid and blind to know what's going on around her.
- Lack Of Stamina: The same person who wishes that she could somehow or other drop her kids off on someone forever because she finds motherhood boring and unproductive wound up selling her business to someone who wanted to work because being in charge hurt too much.
It seems to me that the reason that Elly's disastrous ineptitude and stupidity is somehow magically not her fault is that she's the creation of a woman who got fired from any number of jobs because doing what she was told when it was boring was as unfair an imposition as not stopping a complicated procedure to reassure her fragile ego. Since Lynn is a poor fit for the working world and seems to have found steady work under the control of people who expected obedience and consistency a soul-draining and exhausting chore and since she thinks that everyone thinks just like her, it's obvious that any sort of real work is clearly a death sentence.