"I Am Groot" ends with Groot painting a picture of the Guardians of the Galaxy. The photo, which is covered in green glitter, shows Groot wrapping his arms around Gamora, Rocket, Peter, and Drax. It appears to be a nod toward Groot's sacrifice in the original "Guardians" movie. During the scene, an adult Groot wraps his tree branches around all his friends to protect them from falling debris on Xandar. Once they're all inside his shield, you can see his branches grow leaves and there are sparkling lights everywhere.
According to a February 2019 tweet by "Guardians of the Galaxy" director James Gunn, the "First Groot is dead" and "Baby Groot is his son," which means that although the original Groot is gone, the younger Groot still has memories of his father's past.
Missed some Easter eggs? Then make sure to rewatch "I Am Groot" on Disney+.