How Black Desert Mobile Is Different to the PC Version
Of course the story will be different. According to an interview earlier this year in Taipei Game Show, Pearl Abyss confirmed the mobile version shared the same universe but will focus on a different side/path of story.
Diablo style camera angle
It's very obvious that Black Desert Mobile has a different camera angle, one that's quite similar to Diablo's. It makes sense since the game will be played on a small screen through sliding and tapping. An isometric camera angle will literally allow players to see more things.
Although the video didn't show combat UI, it's sure that the skill slots will be different to the PC version. Besides, the PC version's quick slot feature may not be in the mobile version as well.
There will be a different housing system. In the mobile version you will get a private manor system which allows you to build and upgrade and customize the structures / facilities in your own manor. It's speculated that player manor will be instanced instead of in the open world.
From the video it can be found that some other features such as horse taming, siege, and boss raid are slightly different to the content in the PC version. However, it's to be confirmed since the short teaser video doesn't allow us to see too much.
Source: This Is Game