There is no ‘Brothers-in-Arms’ UDA-DUP mural in Belfast.
In the days before and after the UK general election on 8 June 2017, the above image of a mural indicating a partnership between the UDA and the DUP was shared on social media channels Facebook and Twitter.

Where does the image come from?
The image was first posted on Twitter on 1 June 2017 by user L.A.D. (@LADFLEG), which is a self-professed parody site.
This image was copied and republished elsewhere, including a posting on a blog site (PoliticsMeansPolitics.com) that was not parody but (with a provided hyperlink) accuses the DUP of association with paramilitary groups.
Without providing any source details or links to the original image, there is an inference of this subsequent publishing that the image may be legitimate.
Analysis:
The @LADFLAG image is fake. Using an online service FotoForensics.com, an Error Level Analysis (ELA) of the image indicates that the DUP name, logo, and image of Arlene Foster were all photoshopped into the original image (note red highlights):

According to CAIN (Mural Number 1664), the actual mural, located on Boundary Way off the Shankill Road, was unveiled in 2002 during a period of tensions between the UDA and LVF. It looked like this:

As the CAIN website entry describes the image:
“This mural was unveiled during heightened tensions between the UDA and links between Johnny Adair and UFF ‘C’ Company and the LVF. The UDA/LVF feud started following the shooting of Stephen Warnock, and the revenge shooting of Jim Grey. Alexander McKinley and Geoffrey Thomas Gray were also killed in the feud, and Johnny Adair and John White were expelled from the UDA. The feud officially ended on 5th November 2002, though it was only a matter of weeks before another feud within loyalism erupted.”
This mural does not exist today:

Conclusion:
The claim is false. There is no ‘Brothers-in-Arms’ UDA-DUP mural in Belfast.
Image: Brothers-in-Arms UDA-DUP mural
FactCheckNI is Northern Ireland’s first and only dedicated independent fact-checking service and a verified signatory to the International Fact-Checking Network’s Code of Principles. You can learn more about about FactCheckNI, our personnel, what our article verdicts mean, and how to submit a claim.