In order to have a nice and professional profile picture, it requires plenty of components. However, there are some tips to make the profile picture perfect. You can have a look below for reference on How to have a professional profile picture.
The viewer concerns if the one in the photo is approachable, and willing to help or vice versa? A soft smile is the element to show your Approachability and Influence to people.
Dark colored suits/light colored buttondowns
A proper outfit shows your trusted scores by Capability, Competence and Influence to the Recruiter/ Audience.
Head-and-shoulder, or head-to-waist photo
Full body normally gets low scores. Facial expression with a proper show-up of your body helps people get to know you better.
When you try to open your eyes wider, that shows you lack of confidence. In the other hand, when you make a squinch and smile with teeth, you appear more confident, comfortable and attractive. Do you want to try this in front of the mirror yourself?
Avoid to use hat, glasses, hair, glare and shadows over the eyes. Eye length, eye iris and eyebrow determines the likability. The audience would like to see your eyes directly to understand who you are, if you are honest, youthful of competent, trust-worthy, and suitable for the relevant position.