Should I worry that impressions from the garment could cause permanent damage to my results? (Photo)

I would not worry too much about some skin impressions from your garment. Even normal clothing can leave some harmless skin impressions.  The swelling and edema from your surgery will exacerbate the appearance of these impressions.  I instruct my patients to wear the garment so that it applies gentle even pressure over the surgical area. You want to avoid any isolated pressure points. The garment should not be so tight as to cause pain in any area.  Follow your surgeon's recommendations.  

I personally do not use compression the early stages after a tummy tuck because of the risk to the blood supply and the minimal benefit of compression.  If your garments leaving marks it is too tight.  It may affect your outcome in a negative way.

The garment can cause marks on the skin on rare occasions. One can wear a t shirt, a slip or cotton roll can be placed between your garment and your skin. This can act as a buffer to protect your skin. I usually advocate this about 10 days after surgery. Also if you are sitting, the garment can cause a fold that can cause discomfort and marks that are not usually permanent on your abdomen.