From the angle shown, it was difficult to see where the initial contact took place. However, VAR has a number of ways to determine it, just as they do with the millimetre offside decisions, so we have to assume, with the time taken to call it, that VAR had the exact moment which states that it’s a penalty.
Would I have given it as a penalty, no, and it was definitely a dive following contact. But, by the letter of the law, there was contact and as the ref had given a FK, it had to be a penalty on review.