Initially, yes. I know something that the child doesn't know, and the situation is unexpected and physically harmless, which is the foundation of a good joke. Also, it was someone else's child. If it had been my child, I might have chased after the 'wit' who did this and instilled in him a similar level of emotional discomfort.

Then again, the little girl's inattentive parents bear the greatest responsibility here. It took more than a couple of seconds to set that trap. A flat-footed Good Samaritan quite possibly is the least of her problems going forward. Such a pity for her and the world at large that she'll bear the cost of having self-involved parents. She isn't the first; she won't be the last.

Childhood should be a time of joyous exploration and discovery of objective reality. Children should avoid what can hurt them and not fear what cannot hurt them. Inanimate bits of colored plastic cannot hurt a child, and yet there she is, crying in abject fear. However, given a choice between this unnecessary emotional shock and, e.g., her possibly running out the door of the store and into the parking lot, it very well might have been the lesser to two evils.

Evil... but lesser.

[And, no, I don't get invited to a lot of parties.]

When my kids were younger each had their own quirk similar to the Dino's in the image. More than once certain items were placed to steer either of them from places I didn't want them to go.

That’s pretty funny.

My guess is that the parents set up this picture.