While studies suggest that maternal smartphone use causes disruptions to mother–infant interactions and distress to the infant, little work currently explores how mother–infant dyads co-regulate after periods of technoference, or how different modes of smartphone use impact co-regulation strategies within the dyad. This pilot study used a modified still-face paradigm to explore differential impacts of texting and phone call on mother–infant emotion regulation behavioral strategies after technoference. We recruited 46 mother–infant dyads, living in Scotland, where the infant was aged 3–6 months old. Linear modeling identified that after a phone call, synchronous negative affect significantly increased compared to free play (t(131) = 3.26, p < .01, d = .68), while after texting, synchronous negative affect was significantly higher still (t(131) = 7.03, p < .001, d = 1.47). Conversely, synchronous positive affect significantly reduced after a phone call compared to free play (t(131) = −4.42, p < .001, d = −0.92) and significantly reduced further still after texting (t(131) = −6.69, p < .001, d = −1.40). This has direct implications for maternal support and education, suggesting that communicating using audio functions rather than texting has the potential to reduce experiences of mother–infant negative affect after episodes of technoference.