My pet peeve is people writing "disclaimer" when they really mean "disclosure".
A disclaimer denies responsibility. So if you're including a disclaimer that you work for Google, you're essentially saying that you take no responsibility for the consequences of your comment because of your employer.
Charitably, I think the idea is something along the lines of: "Disclaimer: I take no responsibility for you mistakenly assuming that this comment is a independent review by someone unaffiliated and impartial.". (Though practically, it's probably just sloppy phrasing in a context where that sloppiness isn't much of a problem.)
A disclaimer denies responsibility. So if you're including a disclaimer that you work for Google, you're essentially saying that you take no responsibility for the consequences of your comment because of your employer.