It is possible to load two images side by side into your proposals.
Simply insert two images into the text editor using the insert image icon, not via the full width option. Align them both left, and they should automatically rescale to sit next to each other nicely.
Step 1: Call up the editing menu in your proposal by pressing Enter. Scroll to the Insert Image option.
Step 2: Insert your chosen image, then click on it to bring up the Alignment menu. Click the Align Left option for both images.
Step 3: Your two images should now sit alongside each other within the proposal.