Reason for the deletion of my post

Hi respective forum editors,

I have posted a coloring page on the types of motor vehicles earlier. It was put into pending section for a specific reason. So i have made a few more pictures related to the topic. But when i logged in yesterday, i could see that my post's status changed to deleted. It is really disappointing. I have made a huge effort to make these coloring pages. So can you please tell me why my post is deleted without giving me a prior notice.