Announcements is a new feature currently rolling out in Teams, Announcements help you to make the conversation standout in the channel. There is a main heading field as well as a subheading along with the option of a background colour/image able to be applied.
To start, click the Format icon under the new conversation box:
Traditionally, you would have then seen:
But now, you would then see the option for Announcement under a drop down menu:
You can have a coloured background:
Or pick a picture:
You can then pick the part of the picture you’d like as the background if it’s bigger than the minimum size
Once posted, there is a new icon to show that it’s an Announcement
At the moment there doesn’t seem anyway to restrict this, but that may come in a future release.