Some translations set each line of poetry farther to the right than the rest of the text to make it easier to read. The ULB does this with the poetry in 1:2-11.
God does not approve of prostitution, but he told Hosea to marry a prostitute so that the message of Israel's unfaithfulness would be shown to the people. (See: [[rc://en/tw/dict/bible/kt/faithful]])
Hosea's marriage to Gomer is a metaphor for the kingdom of Israel's relationship to Yahweh. Israel was unfaithful to Yahweh and broke the covenant with him. Gomer was a woman who was unfaithful to her husband broke her marriage agreement with him. (See: [[rc://en/ta/man/translate/figs-metaphor]] and [[rc://en/tw/dict/bible/kt/covenant]])
Hosea 1-4 is controlled by a metaphor that Hosea lived out. He was personifying the relationship between Israel and Yahweh. Hosea played the part of Yahweh, and Gomer played the part of Israel.