Using add_sticker on a post with an image creates unexpected behaviour #16
Description
Using add_sticker on a post such as https://discord.com/channels/257554742371155998/1346950143944953858/1423918385703555103 appears to work, but the "sticker" will not appear on the graph.
/stickers initially let me see and remove these images, but I left one in my stickers for a while, and then when I came back it came back with an "unexpected error occured" message.
Probaly just needs some checking in the add_sticker code that the sticker is actually a sticker, and to refuse to add it when it is.