Except for the E/G# buttons on each side, the layout is what you would expect from the top 4 buttons on each side of the middle row + the outside row of a 30-key, 3-row D/A anglo in Wheatstone layout.
Thus, imagine a 30 key anglo concertina with no "inside row." For simplicity's sake you can imagine that it's a C/G.
If you can play settings of tunes using the C row + accidental row of a Wheatstone-layout C/G concertina, many of those settings will finger similarly on the 2 rows of this miniature (but transposed up a step, or more likely here a step plus an octave). On a 30-key C/G anglo, the F# note tends to be the one note that's only found on the G row. Transposed up a step, that F# becomes G#. Places were found for that note, in 2 octaves, on the draw on the outermost buttons of the outside row of this miniature. The 2 octaves of E on that outside row are duplicates of the notes on the main D row, in reversed bellows directions.
A clever system to maximize the fully chromatic range of a small instrument, while still overlapping with part of a familiar anglo layout. To make a miniature feel more familiar for many traditional styles of music, some players might prefer instead to have a different subset of the layout of the traditional anglo included -- to have more of the two inside rows (the C and G rows of a C/G, or the D and A rows of a D/A) available -- but that would result in more duplicate notes and less chromatic range. Either way makes perfect sense depending on the player and his or her intended use of the instrument.
Edited by Paul Groff, 23 November 2013 - 09:41 AM.