In PreprLabs, there are two kinds of skills that display on your profile: regular skills, and Verified Skills.
Where regular skills are any talent you want to declare, Verified Skills are capabilities that you have actually demonstrated on the platform. You gain Verified Skills by submitting a project to a Challenge that is tagged with them.
For more information on how Skills work on your profile, see this article.
For example, if you submitted a project to a Challenge that listed Innovation as a related skill, you would gain Innovation as a Verified Skill on your profile.
Clicking any skill tag under the Verified Skills section of your profile will reveal which projects you submitted for the skill to become verified. This lets you link your declared skills to your actual work.