Hi dkm,
Imagine for one moment that you are an Super-Hyper-Expert Trader

How did you trade that period (from 15:05) ?
My opinion:
1. At the beginner of the 15:10 bar I reversed my long trade to short because ES touched the LTL and PRV is saying decr black vol (also YM had a VE and now it has decr black vol)
2. 15:10 bar ends red and 15:15 is red too (exactly what we are expecting). We keep our finger on "reverse" button if for any chance we see incr black volume (what we need to see for 'change').
3. At the beginner of 15:20 we see black, but PRV is saying decr volume. We know decr black vol in up trend is "lateral movement". So, we wait and Hold.
4. 15:25 bar wants to go higher at the beginner, but there's no volume to break LTL at ES (and at YM) for a 'volatilty expansion'. Peak YM volume bar is lower. We Hold.
5. 15:30 and 15:35 starts with decr vol. They dance between red and black, ending both to be black. YM at this time (from 15:32 until 15:38) is saying Hold, decr volume. So as decr black vol = Lateral, we Hold (possible flaw here).
6. Now, the hard part. 15:40 bar starts to go up, we see incr black volume at first, exactly what we don't want to see, we get ready to press "reverse". But we think: LTL is a bit far away, to reach LTL we need at least a black volume peak like the one at 15:05. Also, we know we should be already in our ND traverse to RTL(retrace). 1 Minute inside this bar tell us that the peak will be lower. YM volume peak bar (15:40) at that time is definitely lower. We start to think this may be a FTT. 2 min after we see an intrabar gaussian shift to red and YM going lower too. We hold.
7. At 15:48 we see a R2R in YM.
8. At 15:52, YM has touched LTL with incr red. At 15:54 we see decr black. We exit the short trade with 5 pnts
This may be one of many interpretations. But what matters here is: What's your interpretation of this period if you were an Super-Expert trader ?
Regards,