어서 이러다

be acting like this because of something

이러다 is a stand-in verb meaning 'do this, be like this', pointing at whatever is happening right now, and -아/어서 supplies the reason: 그 돈 아까워서 이러냐? 'are you being like this because you don't want to waste the money?', 나 왜 장독에 갇혀서 이러고 있는 거야 'why am I stuck between these jars like this?'. 이러고 있다 'be sitting here like this' is the commonest shape.

Register: casual, often exasperated