I think it is ok to do, but wierd.
I know your point about some people being showy. I think they have the same idea the Israelites had for putting unfashionable fringe on their garments (per the WTS version anyway)--to purposely show they are different, to set themselves apart.
That is distasteful to me personally. A person can pray without doing it in a way that draws attention. I guess I wonder why people opt for the more attention-drawing approach when another approach is available.
I similarly have difficulty when dubs attend funerals or weddings in a church they know stands for prayers, plunk themselves down and refuse to stand up. That draws attention. They could easily sit in the back so as not to be disruptive, or just stand in the back for the whole ceremony, or not come at all. Yet they choose to use the most attention-drawing approach when other approaches are available.
I see no logical reason to put on a show in public unless you're trying to use it as a stage to show off your religiosity.