Hello... To better understand “across” I presented examples and my judgments. I hope to be commented...
1. The sun is going down across the river. This can mean either one of two below. A: The sun is going down at the place located across the river. B: The sun is going down crossing the river.
When 'across' is before the verb, it means #A. However when it's a person you need to decide whose perspective it is from, yours or theirs:- "Across the street, Joan was running away" can be felt from her perspective (close) or yours (distant). d