A Knowledge Panel is Google’s representation of facts about your brand. It includes facts it deems relevant. An entity has to be well-recognized or “well-entitized” for a Knowledge Panel to appear.
It means Google has gathered enough reliable and consistent information about the entity from various sources, understands the relevance and relationships with other entities, and has built trust with that information. Therefore, a Knowledge Panel suggests that the corresponding entity is understood and acknowledged by Google for its unique identity and contribution to its particular field or area of expertise.
An information-rich Knowledge Panel demonstrates that the entity has been well-entitized or well-understood by the algorithms. It shows that Google trusts the information it has gathered about the entity and that the entity is notable enough to deserve its own Knowledge Panel.
A Knowledge Panel is a “stamp of approval” from Google.