The table, in theory. But in playtest I have seen players think of something between sessions and then present to table for brief workshoping.
Oh, I like that! gives players room to come up with something on their own but still lets the table shape it together. btw, I've honestly had a lot of fun chatting with u about your games haha <3 would u be okay with moving our little game dev talks over to discord or somewhere else? totally fine if you'd rather keep chatting here tho!