Peel strips from cucumbers to create a decorative edge; cut cucumbers into 1/2-in. slices. Using a melon baller, remove a small amount of cucumber from the center, leaving the bottom intact., Place the cream cheese, salmon, milk, lemon pepper and dill in a food processor; cover and process until blended. Transfer to a small bowl and season with salt and pepper. In another bowl, beat cream until stiff peaks form. Fold into salmon mixture., Pipe or dollop mousse onto cucumber slices; garnish with dill. Refrigerate until ready to serve.