As you possibly already know, shichimi means seven flavours. And so, it consists of seven spices (the chief of which is chili pepper, sure, but it wouldn’t be shichimi without the others). There’s also a plain “just chili” kind in much the same container as what I seem to be spotting in that fourth picture. I’ve tried that too, of course, as well as just regular Sichuan pepper, in ramen, and I have to say shichimi wins out by far. So accept no substitute ;)
Shichimi is also awesome on pizza, by the way, especially if you like it slightly hotter than the norm.

(And just so you know, I would personally consider putting it in the miso a little rude. Miso is all about subtle flavours. But then again, in a dive kind of situation, it’s not like they’d actually mind. Just avoid doing it in Ye Olde Expensive Sushi Joint(tm) )