You cannot choose the size of your implant by looking at pictures and then picking a number. The overall size is a combination of your breast, chest, and implant.
The same size implant will produce different results in different people – just like the same dress will look different on different people even if they are the same height and weight. What may have been a good size for your friend may not be a good size for you.
Generally, sizes you see on the internet are sizes of the implant used, not the overall breast size.
The surgeon can look at photos you like to understand what you are aiming for, but unless there are measurements with the photos, no surgeon can tell the size of the implant or breast from the image.
If you have size 6 feet, you can get into a size 5.5 and 6.5 shoe. You cannot pick any size shoe as it has to fit your foot. And so it goes that you cannot fit any size implant. It has to fit on your body and fill out your breast.
It is a similar case for the style of the implant. Just as shoes come in different styles (flats, high heels, or stilettos), implants also come in different profiles or styles including moderate, high, and extra high. Profile means how far the implant comes off the chest (not how high the implant sits up on the chest). Your implant is a circle, so it is as wide as it is high.
In your pre-op consultation, instead of asking for a size/cc’s, try to define the look that you are going for and let the surgeon work the number out.