PhotosPicker half size

I want to display a PhotosPicker in "half size " with the .presentationDetents([.medium, .large]) approach, but I cannot make it work. Here is a code example. If you run the example you will see that the bottom button opens a sheet in half screen. The top button will open the PhotosPicker, but not in "half size". Any help or info is greatly appreciated.

import SwiftUI
import PhotosUI

struct ContentView: View {
  @State private var showingGreeting = false

  @State private var selectedItem: PhotosPickerItem? = nil
  @State private var selectedImageData: Data? = nil
  var body: some View {
    VStack {
      PhotosPicker(
        selection: $selectedItem,
        matching: .images,
        photoLibrary: .shared()) {
          Text("Open PhotosPicker")
            .presentationDetents([.medium, .large])

        }

        .onChange(of: selectedItem) { newItem in
          Task {
            // Retrieve selected asset in the form of Data
            if let data = try? await newItem?.loadTransferable(type: Data.self)

            {
              selectedImageData = data

            }

          }

        }


      if let selectedImageData,
        let uiImage = UIImage(data: selectedImageData) {
        Image(uiImage: uiImage)
          .resizable()
          .scaledToFit()
          .frame(width: 250, height: 250)
      }

      Divider()
      Button("Open sheet in half screen") {
        showingGreeting.toggle()
      }


      .sheet(isPresented: $showingGreeting) {
        Text("Hello there!")
          .presentationDetents([.medium, .large])
      }

    }


  }

}



struct ContentView_Previews: PreviewProvider {
  static var previews: some View {
    ContentView()
  }
}