The image left is on the 1892 edition of the Rödelheim Machsor, the well known German Jewish holiday prayerbook. It seems to represent the holidays, and I can make out most items. In the center are the Tablets of the Law, for the holiday of Shavu’ot. At the bottom, we find an incense burner in front of a shofar, representing Yom Kippur and Rosh haShana, respectively. The shofar doubles as a stringed instrument, representing the Levitical chants in the Temple. Left, above the shofar, is part of a trumpet, again evoking the Levitical musical performances during the Temple service. To the right and left are myrtle and date palm branches, two of the four species held during the Sukkot services.
However, I am mystified by the other four symbols. On top is the sun, which I am not sure what it is doing here; is it an allusion to Pessach, which always falls out in the early spring? Is it actually a radiating matza, rather than a sun? Immediately to the right of the Tablets of the Law is a structure that could be a building with lots of windows, a box for sorting little items like nails, spices, or whatever, or it could be a book with a very peculiar cover; I don’t know. On the immediate upper left of the Tablets is a kind of tube, which I cannot make sense of, either. Finally, on the left side, there seems to be a kind of chain or arc connecting the trumpet, the shofar or the myrtle branch to the sun, which I can’t interpret, either. Do you have a suggestion? If so, please leave a comment.
Mikolot Mayim Rabbim 
Building with windows: Beis hammikdesh/Channeke? Besomim box? Cohanitic breastplate? Seifer/learning? all not very convincing.
Tube on the left: Megille? (which is davke not tubular, though)
Sun: could be rather random, or God (not as the sun but as radiating in a symbolic way)
I like your megille suggestion, but upon reflection, I doubt the image includes references to either Channike or Purim, since it graces a set of machzorim, none of which is for either of those two holidays. I likewise don’t expect any references to Shabbes, since all three are covered in the regular siddur (ok, the Sofoh Weruroh edition, with all relevant piyutim for special Schabosaus, and the Krauwetz for Purim – still no need for Machzorim, which anyway don’t deal with those days).
Right, makes perfect sense – contemporary tfilles don’t have the same image, after all.
The sun might simply stand for the circle of the year.
Chatzotzros (the straight silver trumpets) are not just another Levitical instrument.
-micha
וּבְיֹ֨ום שִׂמְחַתְכֶ֥ם וּֽבְמֹועֲדֵיכֶם֮ וּבְרָאשֵׁ֣י חָדְשֵׁיכֶם֒ וּתְקַעְתֶּ֣ם בַּחֲצֹֽצְרֹ֗ת עַ֚ל עֹלֹ֣תֵיכֶ֔ם וְעַ֖ל זִבְחֵ֣י שַׁלְמֵיכֶ֑ם וְהָי֨וּ לָכֶ֤ם לְזִכָּרֹון֙ לִפְנֵ֣י אֱלֹֽהֵיכֶ֔ם אֲנִ֖י ה’ אֱ־לֹהֵיכֶֽם׃
Also in the day of your gladness, and in your appointed seasons, and in your new moons, ye shall blow with the trumpets over your burnt-offerings, and over the sacrifices of your peace-offerings; and they shall be to you for a memorial before your G”d: I am the L”RD your G”d.’ (Numbers 10:10)
So indeed, they are no ordinary instruments, they are clearly linked to the festival services! Thank you.
I think Lipman’s suggestion that the apartment building is really the Choshen makes the most sense. Count the windows, I mean gemstones. Juxtaposed with the Tablets it makes (some) sense. To really kvetch things, on Jaum Taubh there is the Birchas Kohanim.
I’m not convinced those are supposed to be hadassim and a lulav. What does the urn represent? If this is just overflown 19th century book art, then the sun needn’t mean anything either.
I must admit the capsule/ “megilla” has me scratching my head.
I like the Birkat Kohanim suggestion – so it would be the Choshen (breastplate). Thanks.
The urn clearly represents the incense burning pan of the Yom Kippur service, though it clearly was drawn the the liberty of “overflown 19th century book art.”