Door staff are becoming quite widespread in the town, sometimes as a requirement of the license, sometimes as self-preservation. I think this one must be the latter, as the presence seems to be only part-time.

If you saw the same chap I have seen there a few times he looks pretty fearsome, but is perfectly civilised.

BTW, I've a hunch they don't like the term bouncer these days, too clear a description. Obfuscation rules, UK? 8-]