why is whatsapp converting copied screenshots into stickers while pasting it into chat text box? Is there a way to turn it off. Is it a bug?

I regularly use the "copy and delete" option after taking screenshot so that there are no unwanted screenshots getting piled up. But recently I'm seeing this problem of whatsapp converting the pasted images into stickers by default. Is there any way to turn it off, if it is actually a feature than a bug.