Is this content spamming? Multiple images in single asset file.

You can always tag a user in a post, if you want that specific user to react to your post. But they can do that also on the original post. Use a @ and add the user's name. If the user has answered the thread, you can even select the user's name from the suggestions, else you will probably need to add the full name. Even if it also works otherwise, I suggest you use correct capitalization. And sometimes, if there are a lot of similar users, the user you want to get does not get suggested. I suppose that is a bug in the forum software. So @Muhammad Mune27050185f346 will get you tagged: 

😉

(...) it is not advisable to submit several images in one asset. (...)

By @RALPH_L

I may disagree here. As this is a simple asset, including several views into one will make this asset more interesting to the buyer.  The black and the white screens could be put in separate files, however. And to be sure, as a buyer, I would expect this to be a PNG file or a vector file.