Breast Augmentation: Moderate Profile plus/or High Profile
I believe that your result is good, however, a frontal view will give us more information pertaining to the cleavage and overall breast shape. A moderate profile plus implant is an excellent choice because it offers a more natural appearance than a high profile implant. The high profile device tends to make the breast look more globular (ball-like), whereas the moderate profile device is preferred most often. With the information given, I suggest substituting to a moderate profile plus implant.
Switching implants could make you look more flat
The high profile implants have more projection, ie, are taller. Swithching to a mod + ( I would not use a mod implant in you - these are for women with wider ribs) will maintain your volume but with less tall implants. I would think long and hard about this - your pic reveals a reasonable result and an implant replacement procedure may not lead to the type of improvement that you think you will get.
Profile of breast implants can be changed.
1) But, changing the profile of breast implants will not necessarily make you look more natural. How the surgery is done, and implant size, are more important.
2) In the picture, your result looks good. Perhaps you should leave well enough alone.
Switching from high to moderate
Judging from the one photo you provided, your results look pretty good. High profile implants can be used to address sagging. You may need a breast lift if you want to switch to moderate profile implants, so you may want to reconsider your decision.
Looking over your photos, I would have to say that your surgeon has produced a nice natural result. I am not sure how much more natural you would like to look. Remenber the more breast surgeries one has, that more difficult it will be to achieve a good result.
You have a good result, I would say leave things alone.
If you are not happy with the high profiles because there is too much projection, you can always switch out to a lower profile implant.
Changing breast implant style after breast augmentation
Although you only have an oblique view of your breasts, from what I can see, this is a very good result and your breasts look as natural as possible with a breast implant.
I do not think switching to a different style of implant will make any difference, as the final result depends on how the pocket was created for the implant.
Please remember, every time you have surgery complications, although rare, may occur. My advise is to leave your breasts alone!
Switching from high profile breast implant to low or moderate profile
This isolated view makes your result appear excellent. Perhaps the frontal view would make the appearance of the high profile implant more noticeable. Switching to a lower profile is possible but it is not without its risks. It will increase the base diameter of the breast while diminishing the projection.
Suggestions for improvement in BAM
You don't give me enough information to give a complete answer. However, based on your photo, you do have pretty breasts. What I see is that the breast mounds and nipples are low. You should discuss a possible lift and possibly moderate plus implants of a larger size. If the nipple length bothers you, that can be reduced.
High profile vs moderate profile
I would agree that you have a nice result but it depends on what you perceive of as a natural result. Your plastic surgeon did do a good job by placing the implants partially under the muscle and not over-sizing you. In a frontal view we would be able to see the width of your results but I am inclined to state as well, leave them as they are and give them time to settle. I believe you will find you enjoy this size and style on your frame.