A mini sitting is a full one cut in half. It asks half as many questions over half as much time, and both are dealt from one Premium bank for the exam you have chosen — so what separates them is size, not standard. A mini is not a gentler tier and not a trimmed-down slice of the syllabus; it is the same practice, shorter.
The names invite a wrong guess, so it is worth saying plainly what does not change. The difficulty is the same, the marking is the same, and the range of objectives that can come up over repeated sittings is the same; a mini does not quietly deal the gentler items or steer clear of the harder domains.
What a mini process certification exam keeps from the full
Underneath a mini is the same bank of questions a full sitting uses, marked to the same standard. What you give up in a mini is quantity, not quality: fewer items on the screen and a shorter clock, but no drop in difficulty, no narrowing of which objectives can surface across repeated sittings, and no change to how the item is scored. Shrink the count and the time together and you have a mini; leave the material, the standard and the scoring exactly where they were. A mini is a fair, if shorter, read on the same reasoning a full sitting tests, rather than a warm-up round with the difficulty turned down.