Can I modify the initial shape I clipped a photo to?

[CaroleA]

I know I can clip a photo to a shape by dragging the layer with the photo into the layer with the shape.

I can then tweak the placement of the photo as the shape acts like a mask. That is perfect so far. 

However, if I need to move the photo and it does not cover the whole shape, it shows on the edge.

Is there a way to modify it afterward?

I am thinking that if it were a mask, I could brush off one section, but can I do something like that with the shape that is clipped to?

EDIT: using Affinity Photo

[Brian_J]

With the Move tool selected, enable Lock Children on the context toolbar — you can then modify the parent shape layer without effecting the photo child layer.

[CaroleA]

3 minutes ago, Brian_J said:

With the Move tool selected, enable Lock Children on the context toolbar — you can then modify the parent shape layer without effecting the photo child layer.

Thank you!