LinkedIn doesn’t play when it comes to professional profile pics and neither should you. If you upload a pic to your profile that isn’t actually of you or isn’t even a headshot, LinkedIn reserves the right to yank it.
The 313 million-plus member site is for professional networking, specifically with past and present colleagues, hiring managers, potential clients and investors, and other hopefully business-related contacts. That said, your headshot should be professional. In other words, safe. Appealing to a wide audience. Even a little vanilla.