Every situation is unique. It all depends on why you are veneering those 2 front teeth. If they are retruded and you want to bring then forward into alignment with your other teeth, then it will probably look great. Also, if the 2 teeth are darker than the others and you want to bring them closer to the shade of the others, it will also look great. Remember, you want all of your front teeth to match in basic design and color.
Two veneers can make a GREAT smile! And there is talent and skill involved in this treatment, so the cosmetic dentist you choose must have the skill. Ask to see his or her work. Find out if they have done it before, and if possible speak to a patient. My Patient Concierge has two veneers that I placed and you cannot tell from any angle. She now has a perfect smile and loves to use it! Here is another picture of two veneers post Invisalign treatment. They can make a world of difference!