The consequences are that
an anomalous cyclone resides east of the Philippines, associated with northerly wind anomalies and a decrease in rainfall in southern China.
Both the 'normal' El Niño and El Niño Modoki type I are associated with a westward extension of the western North Pacific subtropical high (WNPSH), whereas the El Niño Modoki type II pushes the WNPSH eastward. The type II causes the typhoon steering flow to have a northwesterly anomaly, making it unlikely for typhoons to make landfall in China.
A growing consequence of this, according to JAMSTEC's webpage El Niño Modoki, is that
Several studies have shown that the ENSO Modoki has become more prominent in recent times, as compared to ENSO, and thereby changing the teleconnection pattern arising from the tropical Pacific. Moreover, the associated decadal changes in the sea level are shown to affect not only the islands of central Pacific but remote regions off California and southwestern Indian Ocean
It has also have been found to affect stratospheric ozone in the recent article The relative impacts of El Niño Modoki, canonical El Niño, and QBO on tropical ozone changes since the 1980s (Xie et al. 2014), with
In the light of an analysis of the observations and simulations, we found that Modoki, as a new driver of global climate change, can modulate the tropical upwelling that significantly affects mid-lower stratospheric ozone. As a result, it has an important impact on the variations of tropical total column ozone (TCO), alongside quasibiennial oscillation or canonical ENSO. Our results suggest that, in the context of future global warming, Modoki activity may continue to be a primary driver of tropical TCO changes.
The most concise definition i found is:
The peak warming of the sea surface temperature anomaly (SSTA) is confined to the central equatorial Pacific until boreal winter instead of propagating to the east.
You may already be familiar with this paper, but I found this passage interesting:
Because of the obvious distinction from the traditional El Niño [Rasmusson and Carpenter, 1982] and even from that defined by NOAA in 2003, we refer to the SSTA pattern observed in 2004, namely, warming in the central Pacific (∼NINO4 region) flanked by colder SSTA to the west and east, as an El Niño Modoki (pseudo-El Niño) event; this term is now popular in Japan and east Asia. (The word Modoki was introduced by T. Yamagata during 2004 while explaining a probable cause behind the abnormal summer climatic conditions over Japan. It has been often used since then by various Japanese Mass Media. “Modoki” is a classical Japanese word which means “similar but different.” A news article also appeared in The Japan Times on 24 July 2004 under the heading “'Mock El Niño' culprit behind heat wave, floods: Professor,” which follows: “The heat wave and floods in various parts of Japan are being caused by an El Niño-like phenomenon in the central Pacific Ocean, a Japanese researcher said Friday. Toshio Yamagata, a professor at the University of Tokyo specializing in climate dynamics, said an increase in the sea surface temperature has activated convection currents and promoted a high-pressure ridge in the Pacific, bringing a hot summer to Japan …”