'Well, he looks like a weird guy, but... his insides are even weirder.' 'That's not helpful follow-up.'
Literal
''Well, appearance [topic-は] weird guy is-[but-が]...... inside [topic-は] more weird is'' ''Follow-up [locative-に] not-becoming is [emphatic-です].''
A comic introduction of a character. 中身 ('insides, contents') is used both literally for physical contents and figuratively for a person's inner character. フォロー ('follow') is wasei-eigo meaning 'to back someone up, smooth things over, help them save face'. フォローになってない ('doesn't constitute follow') is the idiom for 'that's not a save, that makes it worse'. Classic tsukkomi comedy setup.