It literally just hit me half an hour ago after I realized it while looking through all of my pictures taken casually from visiting The Exchange TRX, so hear me out. (Apologize for oversized images, no idea how to resize it in LYN bbCode)
So, I have been walking around the mall and never once did I notice it hiding in plain sight (the only pic I have of it in this angle).

...until I came across it again and started actually noticing how shockingly huge the whole cover-up is, so took a close up pic of it this time (which is directly opposite the Aurum Theatre):

Fast forward to half an hour ago, after wondering how it's weird that it's only a single storey at the top when other Apple Stores I have seen are usually multi-storey, I realized that the pic above is *directly under the alleged Apple Store building*.
I unfortunately did not have a great pic showing both as a proof, so I had to take a screenshot from an earlier video I took that just happen to be at that direction and capture both the building and the covered up two-storey store (circled in red):

Not that I don't think anyone here is gonna doubt that it's the Apple Store, but I have looked up earlier in the directory screen in the mall earlier and confirmed that neither Machines nor Switch have outlets in The Exchange TRX (in fact, you can even look it up on the mall's official app which has the directory feature right now). It makes zero sense for either of them to not open up shop in what's probably the highest end mall in the whole country (even more so than Pavilion), unless...
EDIT: In case anyone's curious about the actual building in question, here's the full pic, right besides Kenny Hills Bakery:

wow thanks for your sharing! this remind me of Apple store in Marina Sand Bay Singapore, always tought it was in the rounded glass building, but didnt know it actually hide inside the shopping mall and connected via escalator, i think it has quite the same concept with TRX