This is a general etiquette question although it could certainly apply to a baby shower.
Suppose a host invited 20 or so people to a function. The host proceeds to cancel said event the morning of the day the event was supposed to take place. The host then proceeds to still have the event later that night but didn't invite all of the people back that he/she canceled on and only told a handful to come back and proceeds to post pictures of said event all over facebook for everyone to see. Would this be poor etiquette? How would you react to the host doing this if you were one of the people excluded from the re-invite the same night?
ETA: Event was canceled because host said GOH was not feeling well. GOH posted photos and host was tagged in photos.