What is missing from Mario Maker for 3DS?

I have heard/read from multiple places that Mario Maker for 3DS is a good port, except that it lacks the ability to share levels online. I am confused by what this means, however, as Mario Maker doesn't seem like something that could exist without sharing levels. So what is meant by "sharing levels"?

I know that 100-man mode still exists. When you play random levels that you are given, are those not other people's levels that are being shared with you? Is it that you cannot see the level code, and thus can't tell your friends to try that same level?

Or is it that the bookmark features don't exist; that you can't browse a list of levels by a particular creator? I'm just not quite understanding what is meant by "you can't share levels" in Mario Maker for 3DS.

Solution 1:

I believe the main complaint is that while you can use Streetpass to share your own levels, you can’t per se make a level, upload it (like the Wii U version) and share the level code. It’s not a readily available database like the console version, so instead you’re forced to use Streetpass versus the Internet to share levels.