This was a great question and I'm sure that many of us have observed this phenomenon - and it took a fair amount of research to figure out what was going on. Finally, with assistance from the satellite loops at Marshall Space Flight Center I was able to piece together an explanation.

The short answer is that the sun glint is only seen (with ease) when the sun passes (overhead) over water. Cloud formations and land masses do a lousy job of reflecting the sun. The sun - relative to the position of the earth - crossed overhead the Equator northbound on March 20, the Spring Equinox. It will be overhead at 23.44 degrees North latitude (The Tropic of Cancer) on June 21st, the Summer solstice - but that is only part of the complex solution of what we see in the satellite timelapse loops. The axis of the earth is tilted from the vertical and the satellite camera is on a geostationary satellite located at about 22,000 miles over the equator. It is positioned to always look down over the same area on the earth - thus the name Geostationary Orbiting Earth Satellite (GOES).

Given all of those various angles to work with, it appears that the sun is reflecting off the earth at the current time at around 8 or 9 degrees North latitude. So for the moment, the sun is shining directly down on clouds associated with the Intertropical Convergence Zone (ITCZ) all the way from the west coast of Africa to the east coast of northern South America. The sun finally reflects off of water west of Panama and the glint can be observed as it reflects westward while passing south of Tropical Storm Cristina in the eastern Pacific.
Cheers,
ED