The comma wouldn't necessarily be included in a context like...
Many top footballers can bend it like Beckham
In that example, the "comma-less" version would naturally be understood to mean Many top footballers can bend the ball the way Beckham can. But if the comma was included, it would normally be understood as Many top footballers can bend the ball. Beckham is an example of a player who can do this (more accurately, perhaps, ...an example of those top players).
It would be quirky in the extreme to omit the comma in OP's specific example, but the important point to note is that just about the ONLY reason for having a comma is to reflect a pause in speech.
Getting technical, OP's adverbial clause like having a garden inside your apartment is more naturally parsed as a sentence adverb. That's why there's a pause before it, to reflect the fact that preceding It looked weird is being "separated out" as a "sentence" for the syntactic purpose here.