We do match reactions received from iOS devices when they are for text messages, as they contain the original text, for example, Loved "See you at 9pm". Thus we can look for the text "See you at 9pm" and show the "Loved" emoji.

However, we cannot match image, GIF, video or audio reactions. This is because they don't contain any reference to the original media message. An example is "Liked an image". We cannot match "Liked an image" to any specific image, so are unable to practically show this as a reaction emoji.