Is there a distinction between 肉夹馍 (ròujiāmó) and 馍夹肉 (mójiāròu)? I saw both 肉夹馍 (ròujiāmó) and 馍夹肉 (mójiāròu) being used in Shanxi province (photos below; neighbouring shops, with the same graphic).  It seems both refer to the same food item (what's sometimes described as a "Chinese hamburger").

In this context, the hanzi are:


肉 = meat (ordinarily pork)
夹 = to place in between
馍 = small bread


Question: Is there a distinction between 肉夹馍 and 馍夹肉?

I discussed this with my friends when we noticed this, but we couldn't identify any reason there's two different phrasings.  I think 馍夹肉 is incorrect, but I'm unsure since native Chinese speakers write 馍夹肉.







Update: Here's another photo I took of 馍夹肉 being used in Shanxi:



The shop 二丫头馍夹肉 is listed at DianPing, along with reviews writing e.g. "店里馍夹肉真不错" and "馍夹肉的馍不错".  It could still be a right-to-left writing style, but this makes me unsure.
The second is just right-to-left writing.  See  Horizontal_and_vertical_writing_in_East_Asian_scripts .
Historically, Chinese was written in vertical columns, with columns progressing from right to left.  In the 20th century a shift was made so that most writing is in rows, from left to right.  


  Today, the left-to-right direction is dominant in [Chinese, Japanese,
  and Korean] ... However, right-to-left horizontal writing is still
  seen in these scripts, in such places as signs [and]  stands selling
  food at festivals.


Think of the right to left horizontal writing as showing just a top character in each of a series of columns from right to left.