You are how the world sees you, and the world sees you from the image you present. This is normally in a portrait photo taken from the shoulders upwards. Professional headshots are normally used in advertisements and social media and those who are familiar with them normally call them MCU photographs (medium close up). In such a case the eyes will be in the top, middle half.
In the world of entertainment, actors and singers typically use their photos which are attached to a portfolio in order to give the director or recording studio an idea of what to expect. The applicant takes a few shots of him/her in different positions and expressions to show how versatile they are. This is called "looks". Any shot including a person's shoulders are called a tree quarter. Professional headshots normally came in black and white, but changed a while back and now incorporate color. When the actor's photo is uploaded it is done on a database of 8 x 10 in format. The most important feature for any actor is to express exactly what they represent, their face and subject. The color in such professional headshots is natural and shows the facial features clearly.
In a modeling department they normally take color photos, and attach their portfolio, but they may use black and white depending on jurisdiction. In many cases it leads to requests for color photos to see skin tone and other features. Professional close ups are used for advertisements, portfolio's and tear sheets. Comp cards are printed on both sides covering about five and a half by eight inches, usually in color.
Business head shots are almost the same as the ones used by actors, because it is also used for advertising while being digitally produced. These are the kind of photos that show all aspects of the corporate lifestyle and their branding while expressing a part of their personality. If you want to capture the perfect head shot then consider the following elements. The key is to use natural makeup and not light as this will leave the skin uneven. After applying foundation follow it up with a lot of setting powder. Make use of a darker red lipstick followed by lip gloss to make your lips appear even fuller. Eyebrows are very important and should be plugged or waxed a few days before the time in order to let the swelling and red marks disappear. The eyebrows should be dark enough to be noticed in a small window light.
Mascara should be applied and in black if possible followed by blush, but never too much because one can always add some more. If too much is applied then it is difficult to even out. When it comes to your hair, use a product that enhances shine to give that healthy and natural appearance. Professional headshots are very important, because it will give an image of you and the world will react on that specifically. What you see is what you get in the photography world.