Intentional, On Purpose
な adjective
You wouldn't put your idea in a diagram ~like format if it wasn't intentional. Doing that takes a lot of work. So you can only make diagram like things on purpose!
いとてき
This is a jukugo word that uses the on'yomi readings of the kanji. You haven't learned this reading for 図 yet, so here's a mnemonic to help you: You intentionally stub your toe (と) all the time! If you hurt your toe on purpose you can get out of class and work! It's a really simple injury, but you can't do other stuff while it's hurt, so you always do it on purpose to get out of things.
それは意図的に作り出されたプロパガンダの画像じゃないでしょうか。
That image appears to be deliberately created propaganda.
でもそれちょっと、意図的な作り話っぽくない？
But don't you think it sounds a little like an intentionally made-up story?
誰かが意図的に情報をコントロールしているんだ。
Someone is deliberately controlling the information.