The box is a rough estimation of the NEXRAD image coverage. Of course the true age of the last image is unknown, but was downloaded 3 minutes ago, having arrived at 00:55Z (screenshot is from 00:58z). From the position of the returns west of the line, it appears you didn't know what precip you were flying toward, since the coverage area didn't extend very far ahead of you. I've gently prodded iFly to include the CONUS ADS-B radar image for just such occasions, because it happens to me regularly. Maybe you can poke 'em with a cattle prod. A 15 minute old CONUS radar image would at least let me know intensity, size, rough location, and path of avoidance of the weather ahead until the "local" radar image can catch up to me.