The Showtime series "The First Lady" debuts Sunday, and it would appear some folks on Twitter have already gotten some initial glimpses of Viola playing Michelle ... and some are questioning why the actress seems to constantly purse her lips on camera.

One scene in particular has drawn a lot of eyeballs, and people are having a field day with memes and jokes over Viola appearing to constantly put on an exaggerated duck face while she talks to TV Barack Obama.

There's another scene that's popped up, which shows Viola-as-Michelle posing for a photo shoot, and there too she seems to be rocking the kissy pose with dedication.

While it's unclear if Viola maintains this facial expression throughout the show -- to our knowledge, these are the only two scenes that are making the rounds right now -- it does appear she invokes the lip move later in the series as well ... evidenced in stills that Viola herself has posted on social media over the past few weeks.

Michelle does, indeed, purse her lips at times ... but it seems Viola may have thought that's central to her being, 'cause so far -- it sounds like she does it quite a bit for 'TFL.'

As for how the critics feel about it ... it's not good on that front either. "The First Lady" has a Rotten Tomatoes score of 40%, made up of 20 different pros who've weighed in thus far. These reviews aren't always reflective of the quality of any given movie or show, but it seems the industry isn't too thrilled with what they've done here to tell Michelle's story.

Like we said, the show began streaming today -- so feel free to peep it for yourself. There'll be 10 episodes of this performance, so maybe it gets ... better? Time will tell.

FWIW, Viola was taking this role seriously -- despite what people online might say/think now that it's out -- and she even said she was nervous and wanted to make MO look good.