What are Art Stamps?

[. Rarity .]

I keep seeing messages, or threads about these. But it's never happened to me, I've never had blathers talk to me about it

I have all the exhibits open, do I need to update? Or am I missing something. I'm confused on these

 

[Dunquixote]

Hi! Museum day is currently being held and to partake in the event, first you need to talk to Blathers; if you haven’t talked to Blathers until now, talk to him twice (I had this happen when I used an alt and wanted to do the event). The first time he’ll talk about the museum and donations and the second time he’ll tell you about museum day. Once you do that, you go into each exhibit and you should see these little box like items with a stamp and paper on it. There are three in each exhibit. Click on it and you’ll get a stamp. After you get three from each exhibit, talk to blathers and you’ll get a reward (the plaques). It is repeatable each day until the event ends.

 

[. Rarity .]

Oh I see! That makes sense now, thank you. Maybe I'm also on the wrong day, sometimes I forget what day of the month I'm on

I'll check that again, thank you!