Layer Mask is not showing on my image

[janet82539985]

I am teaching myself how to get a watercolour effect using tutorials, the last step of which is to add a layer mask in black, which then should cover my image in white for me then to brush away the areas I want to reveal. However when I add the layer mask my image is still showing.  Any ideas what is going wrong please, as I am following the tutorials to the letter. I've attached a screenshot which I hope helps. Thank you

[D Fosse]

It hides your smart object layer so that the underlying Background layer shows.

[janet82539985]

Thank. you for responding, but I'm not sure this is the issue. I'm
following an excellent tutorial with images and I'm doing exactly what they
do, but I can't brush over to reveal my image, it's the opposite.

[c.pfaffenbichler]

Please post screenshots with the pertinent Panels (Toolbar, Layers, Options Bar, …) visible, not clipped or absent.

You are aware that we do not know what tutorial you are referring to? 

What are you trying to reveal – the original, unedited image or the filtered one? 

What is the next visible Layer beneath the masked Layer in the tutorial – the original image, a white layer, …?