The triangles of the barcodes (there are 5 altogether) give you a hint - had to use my imagination a bit but since I had done everything, the only thing that made sense is the picture...so, just think of old foto albums and how small pictures were held fast into them without glue...then you should have it.
Water calibration is hinted on the leftover popsickle stick next to the head with the 21% underneath. Need to try around a bit in the order of the symbols depicted. Not sure anymore if the baseline was top or bottom row for that calibration (mirrored or not) though, but doesn't take that many tries to find out - and luckily there are no penalties to it.