Why it worked
The video taps into the popular trend of unboxing collectible toys, specifically LOL Surprise dolls, which have a strong appeal to a young audience. The "surprise" element and the desire to collect all the dolls create inherent engagement.
Product placement
LOL Surprise: These are collectible dolls that come in surprise packaging. The video shows the unboxing and reveals of these dolls. They ACT, as the packaging is opened and the dolls are revealed, making them desirable. Removing them would change the video entirely.
SpongeBob: This is a character from a cartoon. It appears on the packaging of one of the surprise balls. It merely APPEARS, as it is part of the branding on the toy packaging and does not affect the video's content. Removing it would not change what happens in the video.