Insert picture changes uses smaller aspect ratio

If I use insert picture or its VBA counterpart ActiveSheet.Pictures.Insert I am getting smaller image dimensions, yet the properties of the image in Excel is saying its 100% of its true size. If I copy and paste the picture into Excel through picture editing software it stays true to its size dimensions as shown in picture editing software.

Why is this and how do I prevent it from changing? It is messing up my image resizing code, because the picture size to cell size ratios change dramatically as it shrinks down the dimensions.