What it is
Bhamsha divides each sign into twenty-seven equal parts of 1°6′40″. 'Bha' means a nakshatra, and the number 27 echoes the 27 nakshatras, hence the other name nakshatramsha. Here the count starts according to the sign's element.
How it is calculated
Rule: in a fire sign (Aries, Leo, Sagittarius) the first part is Aries, in an earth sign (Taurus, Virgo, Capricorn) Cancer, in an air sign (Gemini, Libra, Aquarius) Libra, in a water sign (Cancer, Scorpio, Pisces) Capricorn; then onward in order.
Example: a planet is at Aries 17°. 17 ÷ 1.111 ≈ 15.3, so the sixteenth part. Aries is a fire sign, so the sixteenth sign from Aries: Cancer (one full round of twelve, then Aries, Taurus, Gemini, Cancer). In D27 the planet is in Cancer.
What tradition looks at in it
Parāśara links the bhamsha to the consideration of strength. Tradition reads it, in plain terms, as a way of seeing where a person's natural capacities lie and which way their temperament leans. The D27 ascendant, its lord and the lord of the 1st house are looked at.
How much the birth time matters
On average the ascendant moves about 1 degree every 4 minutes; some signs rise faster, some slower. One part of D27 is 1°6′40″, so a difference of roughly 4–5 minutes in birth time can change the D27 ascendant. The Moon crosses one part in about two hours. In your chart, ePandit shows next to every varga how many minutes of birth-time change would shift its ascendant. In so fine a division even small uncertainty moves the ascendant, so look at it only with a reliable birth time.
How to read it calmly
Read D27 as a second look, not a verdict. Tradition first studies the 1st house and its lord in the main chart (D1), then the running dasha. D27 only helps check whether the same theme shows up here as well. A planet's sign in this varga decides nothing on its own. 'Strength' here is a calculated measure, never a judgement on the person.