I've talked before about what I call the "tender trap." It happens when someone sets up a model or toy steam locomotive and places the tender backwards. Most times, the manufacturers have a unique coupler to join the engine and tender, which makes this error harder to forgive.
Recently, though, I did run across an example
that I couldn't fault the person too much for. On eBay this person had a
1940's Marx train set for sale.
the tender is backwards. Now Marx used the same type of simple coupler
throughout the set, so you can indeed connect the tender in either
orientation to the engine. But take a close look at the tender. The
opening is at the far left -- the opening that should face the
Without that unique coupler arrangement,
there's nothing to indicate to the novice how the tender should be
joined to the locomotive. If you know something about steam engines, you
would know this looks wrong. If not..