Prince Harry, Meghan Markle Official Engagement Pics Transparently Un-Royal?

12/21/2017 6:45 AM PST

Prince Harry, Meghan Markle Release Official Engagement Photos

Prince Harry and Meghan Markle's official engagement photos are out ... but some folks are looking right through 'em ... asking if Meg's outfit is fit for a princess.

Kensington Palace released the royal couple's professional portraits Thursday, taken by celeb fashion photog Alexi Lubomirski at Frogmore House in Windsor.

Lots of people blanched at Meghan's sheer top ... part of a $75k Ralph & Russo gown, which many called inappropriate for a Royal -- especially when sizing her up to Kate Middleton in her 2010 engagement pics with Prince William, where she was fully covered.

Meghan did end up changing into something more cozy/less revealing in another photo -- but that didn't stop the controversy from bubbling.

From how happy the hubby and bride-to-be look in these pics ... we're guessing they couldn't care less.