Update: It is for Amell's wine business.
YUP! Me & #TomWelling partnered up w/ @nockingpoint, because their wine rules! Click link in my bio. use code PURE to join the new monthly club & place your order. You’ll get PURE, a red wine by Tom, & EVIL, my white #pureevil @StephenAmell @nockingpoint pic.twitter.com/Xi3JYRyzkN— Michael Rosenbaum (@michaelrosenbum) December 7, 2018
Original article continues:
With John Wesley Shipp back as the 90s' The Flash in the upcoming Elseworlds crossover, anything could be possible, so how about something connected to Smallville?
While it's just pure speculation right now, Stephen Amell tweeted out a photo from a meeting where both Tom Welling and Michael Rosenbaum are pictured.
"Pretty excited about this one..." Stephen Amell tweeted, which is leading to speculation of a possible Arrowverse crossover with Smallville.
Pretty excited about this one... pic.twitter.com/aUppARdDXb— Stephen Amell (@StephenAmell) November 24, 2018
If there is any truth to the possibility, it would seem that Tom Welling and Michael Rosenbaum would reprise their respective characters, Clark Kent / Superman and Lex Luthor, from the years following the Smallville finale from 2011, so it would give us a peek at what the universe of Smallville looks like today.
Another possibility is that this is some sort of promotion for Stephen Amell's wine company, which is listed in the background.
One more possibility I can think of is that this could be for another project. Michael Rosenbaum did previously let it be known he wants to do a Smallville animated series. Maybe Amell (and Green Arrow) is a part of it?