It's simple. Just think of the wording.
indication means some point in a apparatus indicating some state. The light being emitted bye the LED is directly received by the human eye.
lighting means a surface being illuminated. The light emitted by the LED illuminates something which is then seen by the eye.
Now, what's the difference concerning the devices used for that? It's the optimization for different purposes. In general, to perceive a signal from a LED doesn't need lot of luminous flux, so power output of the LEDs designed for indication is typically way below 0.5 W. In those devices efficiency is not the most important design yield. They are usually optimized to emit in a certain angle at a defined luminance.
LEDs for lighting are more likely to be optimized to emit certain luminous flux and to perform at a certain efficiency.
Another significant difference is color. Indication type LEDs are designed to be perceived with a distinctive color. When filtering only 2.6 k results of 23 k have a white color. So almost 90% of the indication LEDs are colored. Of course, when an indication is needed, the color should be fixed as it tends to represent a state as well. Most common: green=good, red=bad.
In comparison all of the lighting LEDs are white. So the purpose is, to deliver a full spectrum and let the dyes and pigments of the illuminated objects determine the impression at the eye of the viewer.