Square is typically the kind of Company with a great initial product that raises too much money for its own good and end up chasing 500 battles because they have the team do so. Fab comes to mind as well.
Square has a significant problem: their product is mostly used by merchants with low average selling prices (ASP) and their pricing model (flat 2.7% vs. the usual X%+0.3) kills their margins at this price point. On the other hand, their POS, which could/should allow them to sign more sophisticated retailers or restaurants with higher ASP does scale with businesses because it does not have any of the workflow management features that are necessary.
Overall, they are stuck with an unprofitable customer base and with a (beautiful product) and are trying to throw things on top of this to create a consumer product (like the failed Pay with Square thing).