As a former #programmer, I can think of a ton of reasons this /isn't/ a typo—especially since other large buttons are missing a first letter. It's probably a layout (#CSS or DOM) or programming bug. It's also a Q/A failure, but points to a customer who likely didn't care enough to ensure the final product was what they paid for. /The whole thing makes me want to hit my head on the desk.../
But then I think, "I'm retired," and start laughing maniacally.