Is there a pic of that environment somewhere?
No pics (though a 1/6 mine cart would be pretty huge, so its obvious all you'd get is the cart, a tiny bit of track, and a bare-minimum size rock/tunnel backer wall - not that hard to envision.) It was only mentioned in "Ask Sideshow":
August 2nd, 2010...
Q - What does the future hold for 1:6th scale Indiana Jones?
A - Well, we have a rad
Mine Cart environment in the works, and full intent of some Temple of Doom figures a little down the road.
On Oct 27th, 2010...
Q - You’ve indicated recently that you’ll be focusing on Temple of Doom-themed Indy items in the near future. Does that mean there’s a strong chance of getting a 1:6th scale Temple of Doom Indy in his torn shirt outfit? And in addition to that, how likely is it for you to ever produce a Short Round figure, given his smaller scale which would require a whole new body sculpt? Temple of Doom Indy can’t go anywhere without his trusty sidekick!
A - Okay, you may want to sit down for this…
We have indeed started development work on a Short Round figure in 1:6 scale. We’ll be taking it slow, developing Indy, SR, and other TOD characters for release a little further down the road – but we have commitments…
On Sept 30, 2011...
Q - With Episode I being released in 3D in theaters in 2012, will there be any EPI Sideshow representation? A 1:6 Jar Jar Binks or Anakin Skywalker would be very welcome, and it was said in the Indiana Jones Q&A that a 1:6 “kid” body was under development for Short Round that could be used for lil’ Annie.
A - Yah, our development on the
Short Round has hit a snag, so the Annie likelihood may be a bit further off too....
While it all looks pretty bleak, you must remember that both the HT Indy and the Map Room Environment came out of nowhere. Both were abruptly announced (i.e. no hints they were in development) and then released well within a year of announcement. My guess is that when HT decided they'd do an Indy, Sideshow quickly ramped up the Environment to go with it. So Mine Cart, Shorty and those "other TOD characters" 100% rest on HT doing a TOD Indy... or not.
Note that SSC has not answered a single Indy-related Ask Sideshow question in 18 months.