The lower placard comes from left-wing party People Before Profit (web), attacking Sinn Féin for their vote on welfare reform (in 2015 when the Assembly was still functioning – BBC | Guardian). The upper placard has no fine print asserting its provenance, and PBP has alleged that such placards were put up by Sinn Féin (Irish News). “People Before Profit . .. still supports Brexit”. See previously: Hard Border.