Am I being ignorant?

[magdalena]

There is a bilboard encouraging people to donate clothes to Salvation Army and it showes a jacked with a tag. The tag reads " XS! Were you not being lets say... too optimistic?". Here my question comes: why have they used the word "being"? Would it have made any difference if they had spared it? I know about passive forms like "your order is being processed" but that ad confuses me.

[Tdol]

I am optimistic = either now or in general
I am being optimistic = only now
We use being + adjective to emphasise that it is a temporary state not a general one, so we often use it when criticising- he's being stupid, etc.

[magdalena]

so I was being ignorant, indeed :) Thank you!