Line a 9-in. heart-shaped or square pan with foil; set aside.
In a large heavy saucepan over low heat, melt chocolate and shortening; stir until smooth. Pour into prepared pan, swirling to coat the bottom and 1-1/2 in. up the sides.
Refrigerate for 1 minute, then swirl the chocolate to reinforce sides of heart or box. Refrigerate for 30 minutes or until firm. Using foil, lift from pan; remove foil and place chocolate heart on a serving plate.
In a large bowl, beat the cream cheese and butter until smooth. Combine confectioners' sugar and cocoa; add to creamed mixture with milk and vanilla. Beat until smooth.
Gently fold two-thirds of the whipped cream into cream cheese mixture. Spoon into heart.
Insert star tip #32 into a pastry or plastic bag; fill with the remaining whipped cream. Pipe around the edge of heart.
Garnish with strawberries.