The Definition of Phenotype

"The set of observable characteristics of an individual resulting from the interaction of its genotype with the environment." - OxfordDictionaries.com



"The phenotype is the total characteristics displayed by an organism under a particular set of environmental factors, regardless of the actual genotype of the organism. It results from the expression of the genes of an organisms as well as the influence of environmental factors and random variation. The interaction between these factors has often been represented by the following relationship: genotype + environment + random variation → phenotype

The phenotype of an organism does not only entail the observable features such as morphology but it also includes molecules and structures such as RNA and proteins produced as coded by the genes." - Biology-Online.org



"The term phenotype refers to the observable physical properties of an organism; these include the organism's appearance, development, and behavior. An organism's phenotype is determined by its genotype, which is the set of genes the organism carries, as well as by environmental influences upon these genes. Due to the influence of environmental factors, organisms with identical genotypes, such as identical twins, ultimately express nonidentical phenotypes because each organism encounters unique environmental influences as it develops. Examples of phenotypes include height, wing length, and hair color. Phenotypes also include observable characteristics that can be measured in the laboratory, such as levels of hormones or blood cells." - Nature.com


So it does not simply mean physical appearance.