If X is like Y then Y is like X, no?
No.
It depends entirely on what the author is trying to achieve.
For example, if I was trying to exaggerate how grotesque a little fat boy eating a bag of doughnuts was I might say he was like an elephant dipping a bag of buns, but it really doesn't work the other way.
Question to Jesus: What is the kingdom like?
Jesus' Answer: It is like a mustard see that grows into a big tree instead of growing into a small herb.
Except that isnt what the passage says.
Well duh! Do you think I'm illiterate or a complete moron?
Any other options?
Right, but if the mustard seed is like the kingdom of god then it would grow into a big tree instead of a small herb.
Again, you have a different Bible from everyone else.
It really isn't difficult to understand unless you try not to.
Or try to save Jesus from appearing the moron that He was.