All who see your profile on LinkedIn look at your headshot first. It is how they get their first impression of you fast and decide whether they want to read your headline, summary (About) and the rest of your profile.
For more details on assessing your headshot: https://schools.beyondb-school.com/storage/files/16212453189_Evaluate%20Your%20Headshot.pdf
More details at: https://schools.beyondb-school.com/storage/files/16212453189_Evaluate%20Your%20Headshot.pdf