This is quoted from D1Store.

What's Different between the Dual Screen and Power Combos?

The DJI Action 2 Dual Screen and Power Combos are both equipped with the innovative DJI Action but feature one main difference — the bottom module they come with. The Power Combo comes with the Battery Module that extends battery life up to 180 minutes. The Dual Screen Combo comes equipped with the Front Touchscreen Module that is perfect for vlogging. 

D1STORE PRODUCT PAGE where the above extract was obtained from.

The dust has barely settled on the DJI ACTION 2 and it seems like every youtube channel is there to take it's kilo of flesh and I am not going to be any different in the sense that every YouTuber, mentions this wonderful Pivot Ball Mount, this currently isn't available for purchase like many of the DJI Action 2 Accessories, but I have to tell you, it's only in the dual screen combo.

Also I think they overlooked the fact that the touchscreen module still has the same functions as the battery module, as it still has the battery built in to it and it still has the USB C and the Micro SD slot, where I went shopping with this friend, the bloke legit had no idea what the heck he was selling and I was perfectly fine with that, and he used that line, I don't know but do you need a micro SD card with this? and I was like nah it's got 32GB inbuilt storage and he goes cool, and we left the sale pitch at that he made some small talk around the size and said the GO 2 was tiny and I whipped it out of my pocket.

Photo taken from D1 STORE.

This adaptor is something so tiny that, DJI could have easily included it in both bundles but they have opted not too, which sucks cause I am excepting it to be around $39.00 AUD, I have the understanding even the power Module and screen module will be available the pricing I have been giving is $249.00 for the screen module and the Battery Module will be $89.00, weather you're going to see these slide in to the core range at JB Hi Fi who knows but my guess's will be not and I am guessing they will only be available for D1 Store.

Photo taken from the D1 STORE

So clearly the two different setups are different and it functions as it should but I honestly think that the ball joint adapter not being in both combos is a sore move from the team over at DJI. I feel like the fact that DJI hasn't included that, is a let down and I think YouTubers, need to be aware of these two combos and the different offerings.

Personally I slated to pick up the power combo for the clear reasons that, I think that better suites my needs at the moment I don't see where I would be using this for Vlogging, given the wide FOV (Field Of View), thought I might do some VLOGS with it in the future so I would recommend that you guys keep tuned to the GEEK IN DA KITCHEN YOUTUBE channel.