Top two don't half remind my of my time in Houston, TX.
Where the first picture was taken was said to be modelled on the USA and Texas was mentioned.
I'll try King Khalid International Airport, Riyadh, or King Abdulaziz International Airport, Jeddah, for number 2.
You have the correct country there ... an airport serving a city that's approaching a million in population, part of a province of around four million, but no direct flights to London, necessitating a short international hop at the start. A lack of pictures at that intermediate point; I was purely transfer in the terminal, after dark and doing other things like catching up on emails.
The "obvious" answer for 1 & 2 is Bahrain. But why, if you land at Heathrow T4, and get an HC train that will go to Hayes, you need to get off at T1,2&3 to get a picture of an HEx train I can't imagine.
Treat me as a newby to the trains from Heathrow.
The third picture is a shuttle from T4 to T2/3/Central and the fourth the train running the connect service onward from there, in spite of the colours being HEX. It may have come from T4, but the only train showing on the board at T4 was to Central, and on the principle of "get the first available train as far as you can", I took it and changed. The shuttle was a 4 car unit (don't know the number) although I seem to recall an 8 car unit on the books for the shuttle; the 'connect' was 360 205, identified from a second wider photo. Perhaps someone can tell me if this was the normal train / mode of operation and where the connect came from. Maps showed it to start at Central?
On another topic - there is (now?) a ticket machine at T4 selling walkup tickets to offline stations. At upper screens, it did only offer prices that took my breath away, but then on a later screen said "there is a cheaper ticket if you do 'not via London'; I was fortunate enough to know the geography and that that this would work for me. Thankful for small mercies - it
DID» offer, but pity the newcomer who arrives at T4 and doesn't know what to buy ... I might well have been taken in by one of the official touts and spent more than I needed going via HEX; probably as a newcomer would have researched, booked on line and collected from one of a couple of machines also allowing that.