Observation: Sunny day, near noon with sun from behind fisherman. Assume: late spring to mid summer.
If recently stocked trout standing may be OK, if wild or stocked trout that have reverted to wild spookiness I'd be on my knees to keep trout from seeing me.
Assume there is no hatch I'd use a small #14 Whitlock Red Fox Squirrel Tail nymph or Olive mini-bugger with an indicator. Otherwise match the hatch. Grasshoppers might be a good bet too.
Cast to the fisherman's left side of the stream at the riffles and let dead drift. Likely biggest fish in prime spot near what looks like a ledge at the head of the pool that provides both protection and a feeding lane. Guess fish would be in feeding lanes were stream enters the pool.
Then cast just past the weed line working from fisherman's left to right and let nymph drift across the weeds as suspect fish may be hiding in the weeds. If weeds too tall and snag a nymph then cast just short of the weed line and hope a hidden trout darts out to take the fly.

Tight Lines!