。
She prefers dancing at a disco to skiing.
Literal
She [topic-は] skiing [more-than-より] disco [at-で] dance [side-が] prefers.
The comparative-preference frame: AよりもBの方が好き ('prefer B over A'). 方 ('side / direction / option') functions here as 'option' — the chosen alternative. The よりも is emphatic 'more than' (the bare より is also fine; も intensifies the contrast). Note that A is a noun (スキー) and B is a verbal phrase (ディスコで踊る), but the structure works the same way — ~方 attaches naturally to either. ディスコ peaked culturally in 1980s Japan with the bubble-era club scene; today it's somewhat retro vocabulary, with クラブ (club) being more current.