Phenotyping can be defined as: G + E = P. Meaning, the phenotype (P) of an organism (in this case a plant) is the result of the genotype (G), the physiological traits of a plant, and the environment (E) it is growing in. Therefore, the study of the combination of these factors is called Phenotyping. In this simplified definition, the answer to the question mentioned above can be found.
Namely: by applying high-throughput digital phenotyping to plant research, researchers are able to study the traits of plants, such as stress resistance, growth, development, yield and the overall physiology, in relation to the environment. Consequently, by having total control over the environment of the plant, researchers can measure exactly how traits are affected when one parameter is changed, such as salinity in the water. This is all done using non-invasive ever-developing imaging techniques on a large scale, gathering a wide range of valuable data. Some examples are RGB, PSII, Hyperspectral imaging, LiDAR, NIR and Fluorescence sensors.
This data in turn can be analyzed and reported through dedicated software. This way, researchers are able to unlock their vast image data sets and organize them in a clear and intuitive way, leading to key insights and a whole new level of understanding of the plants.