What will be the visible effect of this SwiftUI code?

What will be the visible effect of this SwiftUI code?

struct ContentView: View {
  @State private var showText = false
  var body: some View {
    VStack {
      if showText {
        Text("Welcome")
          .transition(.opacity)
      }
      Button("Toggle") {
        withAnimation {
          showText.toggle()
        }
      }
    }
  }
}