In short, you can. But when the sun shines directly in your face, the smaller interface elements in the reflection will get bleached out, while the larger ones will stand. When the sun is indirect, the reflection can be seen much better.
We typically suggest a few solutions to help get better reflection visibility in daytime:
— Adjusting glass angle (the best reflection image is obtained at 53°)
— Augmenting phone screen brightness (reducing the screen brightness during the nighttime hours and for bright days we'd recommend to put it to the maximum. Please note under direct sunlight it may still be insufficient to give a decent reflection, these brightness parameters depend on the smartphone — and the passive accessory cannon equalize or augment them)
— The color scheme of the interface (green color works best, white is considerably worse, small elements get completely washed out)