I noticed on my dev hub which has the original mode names, they have special icons attached to them. On my main hub I have renamed the modes prefixing with numbers so that they sort correctly in other apps like Room Lighting. This breaks the special icons and I just get a wrench icon.
I tapped the wrench thinking maybe I could pick an icon but I think that just changes the mode.
So..
1- The wrench icon is confusing, usually when you see that it is to configure something.
2- Would be nice if you could set the icon even if its just from a built in list.
Otherwise, if using the default mode names it is a nice touch on that welcome page of the app.