The covenant was signed in September 1912 (as captured in another famous image from Belfast’s City Hall — see Betting Office). The mural above uses the text of the Covenant as a backdrop to a composite of Edward Carson speaking and a row of Ulster Volunteers, formed in January 1913 (see the similar mural First World War).
Murals Irlande du Nord has a post comparing this painted version with the previous plastic version.
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Copyright © 2016 Extramural Activity
Camera Settings: f11, 1/320, ISO 200, full size 2848 x 2848
Carson speaking, unknown year
Carson inspects UVF troops in 1914
text: X03806 Dean Park Carrickfergus
Extramural Activity 
For those who does not read french, my post notes that on the contrary of the recent trend caracterised by the replacing of painted walls by plactic boards, this wall of Carrickfergus had seen the exact opposite.