Fireworks. These AI tools seem very good at replacing textures, less so about inserting objects. They can all "add fireworks" to a picture. They know what fireworks look like and diligently insert them into "sky" part of pictures. But they don't know that fireworks are large objects far away rather than small objects up close (see the Father Ted bit on that one). So they add tiny fireworks into pictures that don't have a far away portion (portraits) or above distant mountain ridges as if they were stars. Also trees. The AI doesn't know how big trees are and so inserts monster trees under the Golden Gate bridge and tiny bonsais into portraits. Adding objects into complex images is totally hit and miss.