Logos are used to brand and define a company. If done right, a glimpse of a logo should tell you what company it represents without any words or hints. In the case above, it is quite obvious what the rebranded logo represents. After 2010's oil spill in the Gulf of Mexico, British Petroleum's (BP) logo was seen everywhere. With the dripping oil and fading colors from top to bottom, you can see what the artist is referring to with the re-made logo here.
In this case, even with the company's initials "BP," and the play on initials, it is still representative of BP. With having knowledge of what happened, you can see what the artist is tryting to convey. Even if you didn't know what happened with the oil spill, it isn't hard to infer what happened.
In the case of Google, they have yet to make any serious mistakes as BP. Instead, they try to keep their logo interesting. They change their logo for holidays and events. With the consistency and with how widely known Google is as a company and browsing device, it is still easy to distinguish their logo. Here are just a few creative examples of what Google has done with their logo since they've distinguished themselves.