Sure, you can RC on anything and everything. Just don't forget to attach some emotion to it. Like "wow, never seen that before" and be genuinly surprised.
The emotion should be something that makes you stop what you doing and pay attention to the moment. Have very high awareness at that moment. As if you just woke up suddenly, you know something is going on, but you don't know what exactly. So you are intensively looking around, trying to figure it out.