Drop-down menu expands photo but resolution does not improve.

In the attached spreadsheet I have a pull-down menu in cell E5. It displays a blown up version of the relevant photos contained in the range C2:D3.

Unfortunately the displayed images in cells F5 and G5 are of poor quality. I want the quality to improve so that it displays with the same quality as shown in cells F8 and G8.

All the data for larger images exists in cells C2:D3. If I expand any of the pictures in those cells, the picture quality improves dramatically.

I realise I could simply make the images in cells C2:D3 larger (also expanding those cell sizes accordingly), but then the spreadsheet would become very large and much harder to navigate. Any suggestions?