Air flow is smooth on both sides of the jib, and the telltales are both streaming back.
TOO TIGHT
leeward telltale WIND WIND windward telltale
This jib is sheeted in too tight. Air flow is turbulent on the outside (leeward ) side of the sail as indicated by the fluttering telltale. Ease the jib sheet out or head up to get smooth air flow.
This telltale on the windward side is fluttering, indicating turbulence on that side of the sail. Sheet in the jib or bear away until the telltale stops fluttering.