Sift the powdered sugar into a medium bowl.
Add the lemon juice, lemon zest, and pinch of salt. Whisk until completely smooth and glossy.
Check the thickness. The glaze should fall in a thick ribbon. If too thick, whisk in milk 1 teaspoon at a time. If too thin, add more sifted sugar.
Glaze the cake. Let your pound cake cool 10 to 15 minutes. Set it on a wire rack over a baking sheet, then pour the glaze over the top, letting it drip down the sides.
Let the glaze set for 30 to 45 minutes until firm before slicing and serving.