It really wasn't a Fire Flower. Two Super Mushrooms appeared from the block at once and they were not like the usual Super Mushrooms that Peach had seen before. The first Super Mushroom was taller, and the second was wider. Immediately after their appearance, the mushrooms quickly "went" in opposite directions. If the princess is quick enough, she will be able to catch up with one of them. However, she did not necessarily have to do this. Chasing mushrooms is not a royal business.
Sorry for bad English. This is not my native language.