You can ask the senior engineers, but nothing beats rolling up your sleeves, diving in and peeling the onion back. If you have a good manager, you need to tell them you need more time to absorb and understand the code base you're working on. They should be more than willing to accommodate, particularly for a more a coder with less experience.

My biggest pet peeve when I send code out for review is someone responding with the superficial bullshit stuff, so it's great that you identified it as a problem. You do tend to get reviews like that from junior folks, but I also see it with really insecure engineers. People start using code reviews as a weapon to take pot shots at each other.

I also think it becomes a problem when you're doing these smaller code reviews as the blog post is recommending; if you're doing bite sized chunks of code, it's really easy to lose context and overlook things which might be performance bottle necks.