Thinly slice the cucumbers and add them to a large bowl.
Cut the avocado directly in its skin into cubes, then scoop the pieces into the same bowl with the cucumbers.
Add the corn and julienned red onion to the bowl.
In a separate bowl, mix the low-fat cream cheese, mayonnaise, lemon juice, dill, honey, and grain mustard.
Season with salt and pepper to taste. Whisk until smooth and well combined.
Pour the dressing over the cucumber, avocado, red onion, and corn. Toss gently to mix everything without mashing the avocado.
Serve immediately, or chill for a bit before serving for extra flavor development.