I am having a hard time understanding exactly what you need.
Based on the diagram you are showing, it seems you want to compute 3 conv stacks, 2 share weights, and the third has a different size image than the two that share weights.
Assuming RGB images, you could setup as follows
input = {torch.Tensor(3,25,25),torch.Tensor(3,25,25),torch.Tensor(3,224,224)}
then use nn.ParallelTable which contains 3 nn.Sequential modules which each contain your convolutional processing pipelines (and you must explicitly share weights when you create them).
Another approach would be to to treat the data as
input = {torch.Tensor(2,3,25,25),torch.Tensor(1,3,224,224)} -- treating the two eyes as a batch to do the same computation on them
then use nn.ParallelTable with 2 Sequentials (one for each convolutional stack)
If this doesn't answer your question, let me know. This part is confusing to me "each input of 224*224+25*25"