In areas of social exclusion, there are greater risks of facing discrimination at school. The teaching-learning processes may contribute toward the perpetuation of this inequality. This research analyzes a literacy event that takes place in a low-income school in Southern Spain. The new literacy studies have come to examine how power relationships and affective bonds work in such literacy practices. An ethnographic method was followed to facilitate a deeper understanding of multimodal literacy. Further, a social semiotics multimodal approach was adopted to analyze the meaning-making social process that takes place in the classroom. The participants comprised two teachers and 17 children, whose ages range from 5 to 7 years. Data were collected in the form of reports, audio recordings, video recordings, and photographs over a two-years period. The results obtained have revealed that the children have been taught writing and reading through a dominant orthodox model that fails to consider the community's and families' cultural capitals. They also show that the literacy process does not grant any affective quality. Neither is there an authentic dialogic space created between the school and the community. This lack of dialogue generates an inequality in the actual acquisition of comprehensive reading and writing skills at school, with instances of groups exclusion, owing to the anti-hegemonic practices of knowledge acquisition.