Today is World Emoji Day, and to get in on the fun, Apple has replaced all of its executives’ headshots with Memoji versions of their faces. Technically, Memoji are not the same thing as emoji. They’re Apple-exclusive characters that are made in the same style as real emoji, and they can’t be included in text or widely shared, like emoji can be, without turning them into an image. But as far as goofy promos go, we’re talking about a made-up holiday anyway, so I think it works.

What’s also interesting about this gag is that it really helps depict how Memoji are best used — and where their limits are. (The Memoji portraits also highlight just how white Apple’s leadership remains.)

There are a lot of entertaining caricatures here that capture the likeness of the person they’re standing in for. Tim Cook’s is particularly good at capturing the wry smile he makes when dodging questions in an interview. But their success seems to be very dependent on whether Apple’s built in a face and hairstyle that fits the person.

Take, for example, Phil Schiller, whose Memoji does not quite match up:

Here it is again, with Val Kilmer on the left:

I’m not really sure what this proves, but it feels right.

When making my own Memoji, a lot of these limitations stood out to me. It’s supposed to be a fun exercise, but your success and enjoyment are really reliant on finding something that matches up with you, and I wasn’t always able to do that. Apple has a really great starting point with what’s in iOS 12 — I’ve seen a lot of good Memoji creations — but it’s also clear that Apple’s going to have to keep building if it really wants to reflect everyone who picks up an iPhone.

Yesterday, Apple also announced that 70 new emoji are coming to iOS 12, ahead of World Emoji Day. The holiday started in 2014 by Jeremy Burge, founder of Emojipedia and vice chair of the Emoji Subcommittee at Unicode, which standardizes emoji (among many other things).