It is different from the Mi 8 SE
Xiaomi is reportedly preparing another Mi 8 variant called the Mi 8 Youth, and images of the upcoming unit were spotted at TENAA.
Unlike the Mi 8 SE, the Mi 8 Youth (or presumably Mi 8X) has a horizontally-arranged dual rear camera setup. As for the notch, the images imply that the Mi 8 Youth has a smaller notch compared to the Mi 8 SE.
Rumored specs include a 6.26-inch Full HD+ display, Snapdragon 710 processor, 6GB RAM, 64GB internal storage, 3350mAh battery, 24-megapixel front camera, and a 12-megapixel + 5-megapixel rear cameras.
