Ideas:

1. If we compare this glyph with the corresponding Tuesday glyph

then we may identify these four differences (i.e. signs):

a) The right arm of Tuesday is somewhat more powerful than that of Wednesday. b) We can see more of Tuesday's legs than Wednesday's. c) Whereas the right part - now as seen from us - of the elbow adornment of Tuesday seems partly hidden, that is not the case with Wednesday's. d) The elbow adornment of Wednesday is written as if it was consisting of two separate parts, each part ending upwards against the elbow. There is no passage from the left part of the elbow adornment to the right.

The last observation (d) I imagine means that the sun (= elbow) occludes Mercury in the middle of its orbit. The elbow adornment (= orbit) is partly hidden behind the elbow.