This is a visual bug in Group that I've had on my hitlist for a while, going to go ahead and take care of it now. (No need to jam this in for this week's release.)
Group currently doesn't allow flex-wrapping of its children, so we can end up with some awkward spacing. This is especially noticeable on TimestampDisplay, which has the timestmap string adjacent to a clock icon. When space is insufficient, the timestamp text wraps and the icon stays where it is, resulting in kind of a crummy looking component.
By allowing wrap, the clock icon can bump down and keep the spacing a little more coherent. See screenshots.