。
She described the scene there in detail.
Literal
She [topic-は] that-place [genitive-の] scene [object-を] detailedly stated.
詳細に is the adverbial form of the な-adjective 詳細 ('detailed') — formed with に, the standard adverbializer for な-adjectives. It pairs naturally with 述べる ('to state, narrate'), already a formal verb of speech, giving the sentence the feel of testimony or formal report. その場の光景 ('the scene of that place') is the kind of phrasing you'd find in a witness statement, an investigation report, or a vivid travel essay.