셀테기 = 셀카 + 권태기 셀카 : selfie 권태기 : period of lassitude, (formal) the stage of ennui (in married life) 셀테기 means "period of boring about selfie" 저는 셀테기 means "I'm bored about taking my selfie recently" You don't need to answer about it.

"저는 셀테기" means "I am 셀테기", but 셀테기 is not a standard word. It might be a variation on 세테기, which itself is a little known dialect word for 새색시 or 새댁 (newly wed bride). If you looked beautiful and happy like a newlywed in the picture, my guess is probably right - then it's a strong compliment.