Just started re-skim-watching the series from the start and got to the Amador episode.

Obviously you'll all remember that in e4 Ward sees the same alien thing that Coulson and Garrett scrawled out in e22.

That scene is just bizarre on so many levels. Who are the guys sitting there and why are they so nonchalant towards a stranger barging in staring at the markings?

My best guess is that the Todorov Building is part of a branch of SHIELD in Belarus, some kind of research facility? Garrett gets 'the Englishman' to order (who he believes to be) Amador to break in, suggesting that level 8 SHIELD operatives would have no business being there. Coulson didn't seem to recognise the name, but it's unclear whether he would've before having his memory altered as he worked on the GH-325 program so may have knowledge on bases where research is being carried out.

The alternative is that it's part of a thus-far unknown and unrelated operation. At the end of the episode Coulson says that Big SHIELD is trying to decipher it, but they could've just been humouring him, it really depends on who is given the images to decipher and whether they have clearance to know about GH-325 and its effects.

The markings also appear for a few seconds in the episode where Centipede captures Coulson and puts him in that memory machine. The markings appear as an engravement on some stone-like substance, and then it flashes to an image of space with a bright light in the centre.