I created a png with a 10% opacity in photoshop. It looks perfect on my laptop and phone. However when I checked it on another person's monitor you could barely see the image. Then when I checked it on my tablet you could not see the image at all. I guess it has something to do with the settings of the monitors? I dont know where to start debugging this. Any direction would be appreciated.
In the above image you can clearly see the faded girl. On some monitors and my tablet she doesnt show.