Panel 1: The evening before Liz has to pick up her glasses finds Elly trying to cheer her up by telling her to wait and see because she's going to look fine.
Panel 2: Liz's Thousand Yard Stare Of Complete Despair™ does not go away when she's reminded that she chose nice frames that will accentuate her pretty blue eyes. This tells me that Elly mistakenly thinks that an eyeglass lens is like a magnifying glass because neither she nor Lynn wore them at the time.
Panel 3: She then tells her a little white lie about how she finds that glasses make a person look charming and attractive.
This is nice of her. She means this. She wants the best for Liz. She doesn't realize that she's pounding sand in a rat-hole because nothing is going to erase the image Liz probably has in her head of looking like Doc Ock in a blonde wig.
Panel 4: Since she shares her mother's belief that talking back to the person who needs to be talked back to is bad form, she glumly thought-bubbles "That's because you don't have to wear them" because she's also passive-aggressive on top of being vain, self-hating and melodramatic.
Summary: What Liz is doing here is making the Classic Lynn move of assuming that "being consoled" means "this person thinks that my feelings aren't real because she haaaaaaates me and wants me to look stooooooooopid." It matters not if those feelings are not what she should be feeling, they're hers and she should be allowed to wallow and hate herself for no clear reason.