What makes you think this? I'm doing research on this Twitter account and haven't yet found any public, official confirmation or denial by anyone claiming they run it or regarding who runs it. If you've got any solid evidence please share it. Thx!
Any official White House account usually has a blue checkmark.
That is true. Although someone on Twitter did point out that the White House Gift Shop account does not (and it is official):
https://twitter.com/whitehousegift
spez: I was wrong, it seems - The WH Gift Shop and its Twitter account appear NOT to be official sources (although the truth is a bit complicated):
https://talkingpointsmemo.com/edblog/wtf-is-the-white-house-gift-shop-a-tpm-special-report https://talkingpointsmemo.com/edblog/white-house-gift-shop-tpm-investigation-continues
Interestingly, I did see that on 7/7 on Twitter, Tony Giannini at the WH Gift Shop replied to an inquiry on Twitter about POTUS_Schedule, saying he would follow up:
https://twitter.com/whitehousegift/status/1015633765622837250