Puree the cucumber, grapes, bell pepper, scallions, garlic, bread, almonds, 1/4 cup water, the olive oil, vinegar and 1 teaspoon salt in a blender on high speed until very smooth, at least 1 minute. Transfer to a bowl; refrigerate 1 hour.
Thin the gazpacho with 1 to 2 tablespoons cold water, if needed, and season with salt. Divide the gazpacho among small bowls and drizzle with olive oil. Top with edible flowers.
Edible flowers are often sold as an assortment. Taste each bloom individually to see if you like it -- some are more peppery than others.
Make sure your flowers are labeled as edible when you buy them.