As I have already commented in other threads on the subject:
1) Most likely we will end this year positive, but it doesn't have to be very positive, just finishing the year at $20k would be a positive return over last year's close.
Exactly. If we started the year with bitcoin pricing 16,000$ and we end the year with bitcoin pricing 16,001$ it will be already considered a positive year, accordingly to the image posted by OP. So I guess a better measuring tool would be to check how much bitcoin has fluctuated in each time period in percents. Although history doesn't repeat itself, there might be some similarities, especially regards the halving which has always been a very positive moment along bitcoin's history, so it might give us some insights of what could happen next.
Am not the image creator, I saw it and decided to share it here, the source is clearly stated. To me, what the image depict is the normal price movement which everyone is familiar with, not the details in percentage or what have you.
We all know btc halving happens within every 4 years, the exact date may not be the same but it always occurs within that time frame, similar to the price movement, we can't say we still expect btc price to continue dipping through out this year to the next. If history of btc doesn't repeat itself maybe btc halving won't occur within every 4 years. That's a repeated pattern.