In photoshop the groups don’t have a thumbnails that makes it s bit narrower. Photoshop doesn’t consider group to be a self contained unit like Krita where group is composited separately and then added to the layer stack, probably that is why they don’ show thumbnail for group.
Also in Krita you can reduce the size of the thumbnails, which might reduce the width, In any case this is indeed off topic please make a new topic