Manual logging creates extra steps
Searching for foods, entering quantities, and checking every detail can be helpful, but it also slows people down. That effort is one reason many logging habits fade quickly.
A photo can create a faster starting point
Using a meal photo gives the system a practical way to recognize context and move toward the portion decision faster. The value is not the photo itself. The value is the reduced friction.
It works best in ordinary eating situations
The approach is most useful when you are making a normal lunch, ordering dinner, or eating something familiar and just want a clearer sense of how much makes sense.
Simple answer
Photo-based guidance is helpful when it gets you to a better decision faster than manual logging would.