It's number+suit+corresponding Major+image+something else for me, and, of course, interactions with Majors, Courts, and between the pips themselves. Here's another
recent thread about pips where I tried to write out my observations in more detail.
For me, the pips are a great fascination though they did use to be a big frustration at the beginning.

Part of that fascination comes from the fact that they are much more 'neutral' in their mood than illustrated Minors. Cards like 10 of Cups, which in RWS deck immediately screams 'happy', or 3 of Swords, which is all 'sad', don't give that immediate impression in TdM and thus can potentially be less misleading (e.g. when the happiness has a sour side to it or when the heartbreak is actually good for your growth). Like an X-ray picture, they show the bare bones of a situation, and it's up to the doctor (reader, that is

) to interpret what they see as 'good' or 'bad'.