“Transmissions” is the second of two back-to-back group shows at Altman Siegel. Gallery manager McIntyre Parker curated the first, which he titled after a line in a poem by Matthea Harvey: “O the sleeping bag contains the body but not the dreaming head.” In contrast to such titular loquaciousness, the show was an exercise in restraint. (Restraint also defines Pied-à-terre, Parker’s gemlike house gallery out towards the ocean, which often shows a single work by an artist in the basement garage.) Whole walls remained empty, and two of the three artists included (Aaron Flint Jamison and Anicka Yi) presented just one work apiece. Centered by Alice Channer’s draped floor-to-ceiling banner printed with a giant image of wet hair and Pantene shampoo and conditioner, the show felt unexpected, charged, and destabilizing. Destabilizing spatially, because of its utter precision, but also destabilizing—in the best way possible—any attempts at coming to grips with what this work values and what these young artists want. By contrast, “Transmissions” is far tidier, and its art historical references are worn more readily on its sleeve. This second and current summer group show is both more conventional and yet more solid than its predecessor. It feels more familiar, too, …