In an elliptical construction, a writer omits some words from a sentence to heighten the effect or tighten the style.
The garden was overgrown, the weeds [were] thick and matted.
In my yard, the flowers come first, the garden [comes] second, and the crabgrass [comes] last.
When using an elliptical construction, do not omit essential words or phrases. (See also comparisons.)
Russia is farther from St. Louis than England (is).
Elliptical constructions can sometimes make it hard to choose the correct pronoun. When in doubt, mentally insert the omitted words to decide on the correct case.