On the first illustration, the body of the second candle closed above the high of the initial candle which indicates a valid break of structure to the upside with a bullish pressure. The second illustration has it that the body of the second candle closed below the high of the initial candle and that's an invalid BOS. A long wick and hammer head looking candle indicates a bearish pressure. With fibonacci tool, you can target 50% of the last candle.