What does the gray top tweet sign above my name mean? TWITTER?

[D Lin]

So the past 3 of my tweets have this "Top Tweet" sign with the picture of a megaphone next to it and the color of the text is gray. This "Top Tweet" text with the megaphone symbol appears above my name at the top left of my tweet. I used hash tags for these tweets as well.

At first I thought my tweets said this because my tweet was the most recent tweet for the hash tag that I put. But after a few hours my tweet still said the same thing even though other people had tweeted the same hash tag later than me, thus indicating it's not a matter of whether the tweet is recent or not.

I don't have a lot of followers on twitter and I know this type of top tweet is different from the actual top tweets that trend because those need a certain amount of retweets/likes/etc which mine don't receive.

Anyone know what this means?