I do like the prettier dice image though I can see why you could have simplified it down for an avatar.

The cover image div on peakd says its min-height is 240px, it's 155px in hive.blog, max width is 1000px. I just used the header I had for my Patreon when I had it (I ditched Patreon) and it looks fine on a small screen but awkward on a large one XD