Look closer.
This is not just a general. This is one of your armies.
Most obviously, this is an army of five divisions. It has already been mobilised (so we'll need to mobilise armies) and it is at full strength (full green health bar).
In particular, note the attrition number at the bottom. That is going to you army attrition (unless PDS are introducing a more advance old age mechanic for characters).
The tweet makes a point that this is Abu Sasha from Kaffa. The reference to Kaffa seem irrelevant enough to ignore for a general... until you realise that this is the army from Kaffa. Kaffa is able to provide 5 divisions to the army of Ethiopia. These are them.
My guess is that the player's interaction will then assign the Kaffa army to a front somewhere (probably representing the borders between adjacent states. What this doesn't show is how the army will be represented on the map.