A woman is making a dirt cage in the sun. She's using it to trap water, making this a dirt dam. If you think about it, dams are just dirt cages anyway.
Something about the woman working hard to build this dam makes her super sexy (せき) to you. Maybe it's because the sun is so bright, making her shine, or maybe it's because hard work is attractive. Who knows.
Currently there are no similar looking kanji which exist in the WaniKani learning system