Some translations indent each line of poetry to make it easier to read. The ULB does this with the poetry in 16:11-12.
Abram married Hagar while he was also married to Sarai. Even though Abram had his wife’s permission, this was an immoral and sinful action. It also showed a lack of faith in God. Sarai quickly became jealous of Hagar. (See: rc://en/tw/dict/bible/kt/sin, rc://en/tw/dict/bible/kt/faith, rc://en/tw/dict/bible/kt/jealous and rc://en/ta/man/translate/figs-explicit)