коновязь в виде горизонтально протянутой веревки(это редкий вариант перевода, обычно picket line – это линия пикета (линия, образуемая протестующими людьми): A picket line is a horizontal rope along which horses are tied at intervals. The rope can be on the ground, at chest height (above the knees, below the neck) or overhead. The overhead form is usually called a high line.CopperKettle)
плакат(у протестующих) While some smiled and held their picket signs high, others were noticeably tense, heads down and eyes darting between the dozens of police that had been weaving in and out of the crowd since the demonstration began. / He held a sign reading "Free Expression" in one hand, and a smaller one with "Free Teresa" in the other. 4uzhoj)