In a medium bowl, beat the softened cream cheese with a hand mixer or whisk until smooth. Add the Greek yogurt and fresh squeezed orange juice, and continue beating until the mixture is smooth and well combined.
Add the powdered sugar and mix until completely smooth, with no lumps. Cover the bowl and refrigerate the cream cheese glaze while you prepare the fruit.
Slice the seedless watermelon crosswise into rounds about 2 to 3 inches thick. Cut each round into wedges of desired size.
Spread a couple of tablespoons of the chilled cream cheese glaze onto each watermelon wedge, being careful not to let it run off the edges. Top with an assortment of sliced fruit such as strawberries, peaches, blueberries, raspberries, kiwi, or halved cherries.
Garnish with fresh mint leaves or edible flowers if desired. Serve immediately. Any unused cream cheese glaze can be stored in the refrigerator and used as a fruit dip.