How carefully do lenders look at rental income?

[Sarah Lorenz]

I have a significant amount of short term rental income on my primary residence this year, which is the only property that I currently own. I will be selling it in 2018 and buying a new primary as well as an investment property. If I have a similar amount of rental income in 2019, will a lender simply see that similar amount and then count that as a two year track record of income, or will they notice the different properties and want to see a two year track record with the same property?