Look at the belly button first. A belly button with visible scars, or a distorted, unnatural looking belly button is unattractive and a sign that says "I've had a tummy tuck" The ideal results look beautiful and natural. Visible scars around the belly button are unacceptable.
Look at both tummy tuck photos, breast augmentation / lift photos and mommy makeovers together. Some women will have both procedures together, others will stage the procedure.
Prospective patients have a host of issues to consider when evaluating pre-op and postop images of cosmetic surgery patients. An outspoken plastic surgeon who is known for some keen observations is often quoted as saying that "A photograph is merely reflected light". Another telling maxim regarding cosmetic surgery photography is "Almost anything can be made to look good from at least one angle." Both of these observations speak to the fact that while such photographs should ideally communicate the true nature of a surgical outcome, there are inherent limitations to the two-dimensional nature of photography.
Look for Consistency
For this reason, as a consumer you should insist on consistency in preoperative/postoperative photography. The positioning of the subject and the size or 'aspect ratio' in the photographs should remain consistent. If one photograph appears to be taken from five feet away and the other from eight feet away, there is no way to meaningfully interpret the 'transformation'. The lighting and color saturation in all of the images should also ideally be identical, or at least comparable. If the pre-op image is in shadow and the postop image is well-illuminated, there is no way to determine how much of the postoperative 'improvement' was provided by surgical technique and how much is just better lighting. A bright flash can conceal a whole host of flaws.
You should also insist on seeing images from multiple angles, as this is the only way to get some idea of the quality of a surgical result in three dimensions when reviewing two-dimensional photographs, and to confirm that it isn't just from one direction that the result looks acceptable. The photography set-up and photographic background should be consistent. Images taken in the pre-op area in front of a bare wall with an exposed electrical outlet and the patient's gown pulled up but hanging down into the image should not inspire much confidence. Body position and facial position should also be consistent. I have seen breast lift (mastopexy) before and after photographs in which the patient's arms were at her sides in the 'before' images, and then the arms were lifted above the head in the 'after' images. Raising the arms overhead produces an instant 'breast lift', so it is impossible to objectively assess the effect of surgery in photographs where body position is inconsistent.
When evaluating photographs, also keep in mind the fact that many examples you see of a particular procedure may not look like you. Part of what makes the practice of plastic surgery so interesting and rewarding for me is the fact that no two patients are exactly alike, and thus each patient requires a fresh and personalized approach. Rather than trying to dissect how a particular result relates to you personally, view it in terms of that patient's particular 'starting point', and whether or not the surgical enhancement is aesthetically pleasing and natural-appearing.
Don't limit your investigation to an examination of photographs. Review the content of a cosmetic surgeon's website thoroughly, and get a feeling for that doctor's individual approach and practice philosophy. Get a feel for whether the website is attempting to provide useful information or is just trying to sell you something. Determine if the priority is communicating the surgeon's aesthetic sensibility, or getting you approved for easy financing.
Also, another important source of information about a surgeon and a surgery practice can come from individuals who have experience as patient of that practice. At Michael Law MD, PA / Aesthetic Plastic Surgery we have many cosmetic surgery patients who are willing to speak to prospective patients about their surgical experience and their results. If you are favorably impressed when you meet the doctor in consultation, ask to speak to someone who has undergone a similar procedure, and if at all possible someone who has a similar 'starting point' or similar preoperative concerns.