Beat egg whites lightly in a large bowl using an electric mixer until frothy. Slowly beat in enough confectioners' sugar to make icing that will hold shape. Blend in lemon juice until the desired consistency is reached.

Arrange cookies about 1 inch apart on a large sheet of waxed paper. Spread icing onto each cookie, allowing it to drip over edges to look like melting snow.

Grease a microwave-safe plate and place 1 marshmallow on it. Microwave until it starts to puff up, about 20 to 30 seconds. Immediately place the marshmallow on the edge of one cookie while the icing is still wet.

Repeat the microwave and placement process for the remaining marshmallows and iced cookies.

Use black gel to pipe twig-like arms on the icing. Create coal eyes and a mouth on the marshmallow using black gel, and use orange gel for a carrot nose. Add coat buttons with silver nonpareils. Decorate scarves or bow ties using red or green gel.