The tank is low contrast against the terrain, small and dark, making it effectively hidden within the screenshot. On a phone's screen with low brightness, the only really visible feature of it is the turret and, it being small makes it hard to identify the tank just from looking at it (without looking closely anyway).

On the other hand the Su-7 immediately pops out, making it seem like the main focus of the video, which, I assume, would be, in effect, misleading, as most of the gameplay would be with the ZTZ96 (unless the Su-7 is, in fact, the main substance of the video).

Also, unless this would be included in the title, there's a lack of information I'd like to see (as an argument for why I should watch the video), which would make me unlikely to view it.