The reason why Flame is [20MB] is because it includes many different libraries, such as for compression (zlib, libbz2, ppmd) and database manipulation (sqlite3), together with a LUA virtual machine.
SQLite is 500kB, Lua is 150kb, zlib is 80kB, libbz2 is 60kB. Together this comes to less than 1MB, not 20MB. You would need an awful lot of libraries like this to get anywhere close to 20MB.
They're likely skipping over a ton of libraries for brevity's sake. It captures data from audio, video, bluetooth, and other sources. A full BT stack is going to be pretty sizable. If there's any compression being done on that audio or video, that could also add to the bulk.
Exactly. I particularly wanted to mention that it's entirely possible to ship software that uses libraries like this but isn't 20MB large. But maybe there are a lot more libraries included than are mentioned here (as another poster suggested).
SQLite is 500kB, Lua is 150kb, zlib is 80kB, libbz2 is 60kB. Together this comes to less than 1MB, not 20MB. You would need an awful lot of libraries like this to get anywhere close to 20MB.